Animated Sprite - the MSDN example

XNA Game Studio Express

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    - Issue with XNA Tutorial and scrolling backgrounds I just tried it and got the same thing. The problem is that the SpriteBatch class is changing the render state of the device. I worked around it by placing the following line right after my SpriteBatch.Begin call: [code] StateBlock state = new StateBlock ( graphics.GraphicsDevice ); [/code] and then the following line right after my SpriteBatch.End call: [code] state.Apply(); [/code] Once I figure out what its setting (it has to be one of the alpha parameters), I'll let you know. It wasn't my first guess... but there are only a few that it could be and generating a StateBlock every frame this way might not really be a good idea. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - How can I draw a flat Sprite in 3D space using transparency/alpha layers? These are the default values I use for standard alpha blending: // enable alpha blending device.RenderState.AlphaBlendEnable = true; device.RenderState.SourceBlend = Blend.SourceAlpha; device.RenderState.AlphaSourceBlend = Blend.One; device.RenderState.DestinationBlend = Blend.InverseSourceAlpha; device.RenderState.BlendFunction = BlendFunction.Add; device.RenderState.AlphaDestinationBlend = Blend.InverseSourceAlpha; // don't write z depth if there is no alpha device.RenderState.AlphaTestEnable = true; device.RenderState.AlphaFunction = CompareFunction.Greater; device.RenderState.ReferenceAlpha = 0; Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Please start new threads on http://forums.xna.com These forums will no longer permit new posts. The XNA/DirectX team has moved their forum support over to http://forums.xna.com . This includes all discussions related to XNA Game Studio Express. We apologize in advance if this creates an inconvenience, but we are very excited about the new opportunities this will offer to our entire community. We look forward to seeing you there! David "LetsKillDave" Weller Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Default pixel shader? I fear I already know the answer, but is there any way to use a 'default' pixel shader This used to be done by specifying PixelShader = null; in the .fx file, but this doesn't work any longer. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - TorqueXNA Ummm, isn't Marble Blast Ultra a bit larger than 50MB I thought I'd also seen some demos that were a bit larger than that as well. Maybe they weren't Arcade demos though. Man, it's rough getting old, what with the senility and all. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - 360 Texture Mapping Problems... Ok ... Just got my 360 creator club membership and tried my first 360 game routines. I have a problem with textures... I'm using DrawableGameComponent's. I'm rendering a tube with a texture and fogging (to black). Camera is inside the tube. The tube is made up of triangles with a repeating texture. Looks great until... I've now added a component that plots a sprite (a simple game logo). The textures on the tube are now drawing incorrectly. Texture seems to stop repeating (when texture co-ordinate goes over 1.0f). This only happens when I plot a sprite (via spriteBatch). Help. I'm guessing something on the graphicsdevice is being set when a sprite is drawn ... but I can't find out what. Does anyone have any ideas I.e. Why the textures stop repeating Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Is it support 5.1 ? im trying to create a game for blind people so... Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - The Last Hero for Dream.build.play you all can soon download a fps shooter in full source code i have updated my website and publish the game story and title hope you all find this interstring read the game story and listen to the game music online best regards Mike and batman Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Contour offset of a polygon Cel shading technics are using a "sort of "coutour extraction algorithm. So if you manage to understand how it works, maybe you coud do your effect. Also, stencil shadows uses a real time contour extraction (from the point of view) to be rendered. This extraction can be done either on the cpu or using shader. So maybe this could be a good starting point for you. Once you have contour vertices (on the cpu side), then simply use line primitives. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Creator's club payment problem Hello, I have a problem with adding my credit card as a payment option I guess it's because I live in country that's unsuported by XBox. I've heard that I can call to support so they can add my card themself I tried that but after talking with the bot I am being disconnected. 3 tries cost to me about $10 :(. Then I've tried to write e-mail to XBox360 support but they told me that I need to call in support... So the question... Is there some way to become Creator's Club member by living in unsuported country Somewhere I saw that I can... But how Thanks Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - looking for prereqs file for a setup and deployment project... I need the prereq files for MDX 1.x and Visual studio 2005 if possible so that my setup and deployment project can require them to be installed prior to installing. Thanks, Devin Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Custom Content Manager - Generics Question Yes, I would probably also use the Type as a key, its a good idea. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Displaying Fonts in XNA?! Thank you Aaron! That's just great. I can load BitmapFont files very very easily in XNA 1.0 as well as texture files. I think many developers should know your XNAExtras. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - XNA 360 Payment Methods The current implementation is not permanent, at least from what I've seen the XNA team say. The current implementation is what could be done given the time frame that they had and the need to make sure security was ensured. Patience young Padawan, and all shall be revealed in time. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - XNACommunityArcade - Need game info / links... Michael Hansen wrote: i think there allso gonna be an update to your xbox360 to corect all the bugs in the xna framework rember you got the xna into your xbox on the fall update and you where programming in xna beta 1 at that time Uhh, we weren't doing Xbox games with the betas. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Line Colours Hi All, In our application we would like to draw thousands of objects each consisting of two LineStrips and one LineList primitive. Each object should be drawn using one colour and so we are using PositionOnly vertices rather than PositionColored. How can we set the colour of an object without using PositionColored vertices Also what is the easiest way of drawing some objects as dashed or dotted We're using DX9 on this. Many Thanks for any help you can give Simon Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Troubles extending the Game class I'm trying to create a base game class for my library that my program's game class will inherit from, but am running into some confusing trouble. Intellisense isn't giving me hints for any of the Game class member variables (like graphics or content for instance). If I go ahead and use them anyway, I get errors when I compile. I can't imagine why the following code wouldn't work, but I suppose I am overlooking something. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Orientation 3D calculation Hello, I really do not know where to put this thread so please mind me So we have 2 meshes placed in a 3D space. Each one of those mesh has a position and an orientation represented by a vector 3 and a quaternion. All vectors are X,Y based we are in a plane Vector3 mobToTargetVector = new Vector3(); //This will hold the vector Arrival mesh -> Start mesh Vector3 mobOrient = new Vector3(); //This will hold the orientation of one of the mesh int rotationSign = 0; //This is for rotation thingy float mobToTargetAngle; //This is for dot product information of the orientation of a mesh and the mobToTargetVector Vector3 crossProduct = new Vector3(); //This will hold the cross product of the upper //We calculate the target to mob vector. Start - Arrival here mobToTargetVector = Vector3.Normalize(this.position.Position - this.target.getPositionDirection().Position); //We calculate the direction vector in the X,Y reference plane. Orientation vector mobOrient = Vector3.Transform(new Vector3(1.0f, 0.0f, 0.0f), Matrix.CreateFromQuaternion(this.position.Orientation)); //The cross product gives out the cosine of the angle. mobToTargetAngle = Vector3.Dot(mobToTargetVector, mobOrient); //If the cosine is too small if (mobToTargetAngle < thresholdAngleCos /*0.978f*/) // if the cosine value is inferior to a preset value, we have to turn a mesh { //So we calculate the cross product crossProduct = Vector3.Cross(mobToTargetVector, mobOrient); //If the cross product is positive regarding the z axis then we have to turn in the anti trigonometric sense //If the cross product is negative regarding the z axis then we have to turn in the trigonometric sense rotationSign = -Math.Sign(crossProduct.Z); PosOrient.Orientation = Quaternion.Concatenate(this.position.Orientation, Quaternion.CreateFromAxisAngle(new Vector3(0f, 0f, 1f), rotationSign * turningSpeed)); PosOrient.Position = this.position.Position; mobMovement.Action = "Player movement orientation"; mobMovement.Origin = this; mobMovement.Target = PosOrient; theGame.theAgregator.writeFIFOBuffer(mobMovement); } However , it does not work, the mesh does not orientate itself rights Regards, Chryso Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Trends in Managed Game Development Yes, you are quite right; I'm new to game development (directX, anyway). I just want to know that I'm making the right start, and not wasting my time (eg. by using C# and managed DX). Don't worry, the first engine that I'm making is 2D :) It'll be a platform for a side-view shooter style game; it's main feature being full real-time terrain destruction on a polygon level. I've never seen this done before (at least not well) except on Red Faction, which was of course 3D :P So, looks like I'll use VS2005, DX 9.0c, and C++ (unmanaged all the way) to make my first little engine. Thanks for your help everyone =) Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - XNA Demos Released I'm glad you found the demos helpful The next XNA demos in the series will cover cameras: first person style, flight simulator style, and third person style. They're essentially C# XNA conversions of the C++ Direct3D version also available on my website. They should be up soonish. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Vertex Buffer Arrays? I am building a city for my game. I need a lot of buildings, so many that they will not fit in one Vertex Buffer. My solution, create an array, sadly this isn't working very well. Here's my code. [code] //this is what m_pVB and m_pIB are set to in the class //LPDIRECT3DVERTEXBUFFER9 *m_pVB; //LPDIRECT3DINDEXBUFFER9 *m_pIB; //VBNum = The number of buildings / the defined number of buildings per VB m_pVB= new LPDIRECT3DVERTEXBUFFER9 [VBNum]; m_pIB = new LPDIRECT3DINDEXBUFFER9 [VBNum]; for(int v = 0; v<VBNum; v++){ ... some code that doesn't matter too much V_RETURN( pDevice->CreateVertexBuffer( 20*renderamount * sizeof( D3DXVECTOR4 ), 0, 0, D3DPOOL_MANAGED, &m_pVB[v], 0 ) ); V_RETURN( pDevice->CreateIndexBuffer( 30 * renderamount * sizeof( USHORT ), 0, D3DFMT_INDEX16, D3DPOOL_MANAGED, &m_pIB[v], 0 ) ); ... fill the Buffers and go through loop again } [/code] The first time I go through the loop it works fine and the second time I get this in the debug menu when I try to create the Vertex Buffer, First-chance exception at 0x7c91b3fb in Game.exe: 0xC0000005: Access violation reading location 0x07df07de. Direct3D9: (WARN) :Alloc of size 272 FAILED! Direct3D9: (ERROR) :Out of Memory creating vertex buffer Direct3D9: (ERROR) :Failure trying to create Vertex Buffer D3D9 Helper: IDirect3DDevice9::CreateVertexBuffer failed: E_OUTOFMEMORY I know I'm not out of memory because I ran this test attempting to make 100 buildings in 10 separate buffers, I've made over a 1000 buildings before. Also I know my code works because if I try to create buildings in 1 buffer using the same code it works. I have also tried making a struct with the VB and IB in it and then creating an array of that, same issue. I have looked for answers, I found a couple similar threads but none were the same situation, and none had any answers. No tutorials I have found use VB arrays either. If anybody has experience with VB arrays or sees a flaw in my code I would love any help, thanks. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Texture Coordinate Issues I want to use a single instance of Texture2D and a single bitmap image for a skybox. The image contains six smaller images that represent the skybox panels. If I use values between 0 and 1 for the texture coordinates, they seem to get rounded. Is there anyway I could use a texture sheet and use values between 0 and 1 as the texture coordinates, or do I have to create an instance of Texture2D every time I want a separate texture Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Managed Direct3D 10 Michael, it��s good to have an official word about managed Direct3D 10. As I have written before something with official support from Microsoft will always better than my own one man show. But as long as you don��t write a fully managed runtime that talk direct to the driver (I thought about this too) I believe you couldn��t be much faster than my wrapper. Maybe if you have access to a better C++/CLR compiler that allows you to use less expensive managed to unmanaged calls. If the last rumors are true the D3D10 hardware problem should be solved in the next few days. But I am sure you already know this better but could not talk about it. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - XNA and isometric thanks for the answers.. i have one last general question.. what is the best way to place objects/enemies/buildings should i put objects and buildings on the map (tilemap) or should i put them as object in a list.. (like moving enemies) if they are an object and stored in a list i could give them attributes (like coordinates, bounding box coordinates,depth etc). what do you think thx Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Weird lightning on custom mesh Hmmm ... I've been trying to calculate the vertex normals automatically, but without any luck. I've discovered that a vertex normal can be made of the sum of all attached face normals. So I've expanded my code with the following piece: // Loop through every start of each triangle for (int i = 0; i < indexData.Length; i += 3) { // Find all 3 vertices VertexPositionNormalColor v0 = vertexData[indexData ]; VertexPositionNormalColor v1 = vertexData[indexData[i + 1]]; VertexPositionNormalColor v2 = vertexData[indexData[i + 2]]; // Calculate the triangle normal Vector3 vt1 = v0.Position - v1.Position; Vector3 vt2 = v2.Position - v1.Position; Vector3 triangleNormal = Vector3.Cross(vt1, vt2); triangleNormal.Normalize(); // Add the triangle normal to the vertices in the triangle vertexData[indexData ].Normal += triangleNormal; vertexData[indexData[i + 1]].Normal += triangleNormal; vertexData[indexData[i + 2]].Normal += triangleNormal; } // Loop past all the vertices and normalize the vertex normals for (int i = 0; i < vertexData.Length; i++) vertexData .Normal.Normalize(); As you can see I've looped through all the vertices and added the facenormal to the vertex normal. At the end the vertex normals are all normalized. Which should be enough for my simple torus object. But still, it doesn't work .. I'm getting the same weird lightning results ... ... just don't understand what could be wrong, here's the total code: /// /// Method to initialize the vertex buffer /// /// protected void InitializeVertexBuffer(GraphicsDevice graphicsDevice) { // Localize properties (as float for easy math) float radius = this.SegmentRadius; float tradius = this.TubeRadius; float segments = this.Segments; float tubes = this.Tubes; // Create doubles for our xyz coordinates double x = 0; double y = 0; double z = 0; // Init vertexList and indexList List verticesList = new List(); List indexList = new List(); // Init temp lists with tubes and segments List<LIST> tubeList = new List<LIST>(); List segmentList = new List(); // Calculate slice offset for float tubeSlice = MathHelper.Pi / (tubes / 2); float segmentSlice = MathHelper.Pi / (segments / 2); // Loop through number of tubes for (int i = 0; i < tubes; i++) { // Create a new segment loopup list segmentList = new List(); // Loop through number of segments for (int j = 0; j < segments; j++) { // Calculate X, Y, Z coordinates.. x = (tradius + radius * Math.Cos(j * segmentSlice)) * Math.Cos(i * tubeSlice); y = (tradius + radius * Math.Cos(j * segmentSlice)) * Math.Sin(i * tubeSlice); z = radius * Math.Sin(j * segmentSlice); // Create a new vertex element VertexPositionNormalColor vertex = new VertexPositionNormalColor(new Vector3((float)x, (float)y, (float)z), Color.White, new Vector3(0, 0, 0)); // Add the vertex to global vertex list verticesList.Add(vertex); // Add the vertex to the current segment segmentList.Add(vertex); } // Add the segment to the tubelist tubeList.Add(segmentList); } // Loop through all of the tubes //for (int n = 1, i = 0; i < tubeList.Count; n = ++i % tubeList.Count) for (int i = 0; i < tubeList.Count; i++) { // Find next (or first) tube offset int n = (i + 1) % tubeList.Count; // Find current and next segments List currentSegment = tubeList ; List nextSegment = tubeList ; // Loop through the segments for (int j = 0; j < currentSegment.Count; j++) { // Find next (or first) segment offset int m = (j + 1) % currentSegment.Count; // Draw the first triangle indexList.Add((short)verticesList.IndexOf(currentSegment[j])); indexList.Add((short)verticesList.IndexOf(currentSegment[m])); indexList.Add((short)verticesList.IndexOf(nextSegment[m])); // Finish the quad indexList.Add((short)verticesList.IndexOf(nextSegment[m])); indexList.Add((short)verticesList.IndexOf(nextSegment[j])); indexList.Add((short)verticesList.IndexOf(currentSegment[j])); } } // Copy the vertices to an VertexPositionNormalColor array for VertexBuffer VertexPositionNormalColor[] vertexData = new VertexPositionNormalColor[this.totalVertices]; verticesList.CopyTo(vertexData); // Copy the indices to an array short[] indexData = new short[this.totalIndices]; indexList.CopyTo(indexData); // Loop through every start of each triangle for (int i = 0; i < indexData.Length; i += 3) { // Find all 3 vertices VertexPositionNormalColor v0 = vertexData[indexData ]; VertexPositionNormalColor v1 = vertexData[indexData[i + 1]]; VertexPositionNormalColor v2 = vertexData[indexData[i + 2]]; // Calculate the triangle normal Vector3 vt1 = v0.Position - v1.Position; Vector3 vt2 = v2.Position - v1.Position; Vector3 triangleNormal = Vector3.Cross(vt1, vt2); triangleNormal.Normalize(); // Add the triangle normal to the vertices in the triangle vertexData[indexData ].Normal += triangleNormal; vertexData[indexData[i + 1]].Normal += triangleNormal; vertexData[indexData[i + 2]].Normal += triangleNormal; } // Loop past all the vertices and normalize the vertex normals for (int i = 0; i < vertexData.Length; i++) vertexData .Normal.Normalize(); // Initialize the VertexBuffer, and insert the data this.vertexBuffer = new VertexBuffer(graphicsDevice, VertexPositionNormalColor.SizeInBytes * this.totalVertices, ResourceUsage.None); this.vertexBuffer.SetData(vertexData); // Initialize the IndexBuffer, and insert the data this.indexBuffer = new IndexBuffer(graphicsDevice, sizeof(short) * this.totalIndices, ResourceUsage.None, IndexElementSize.SixteenBits); this.indexBuffer.SetData(indexData); } Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Quaternion Tutorial I guess that won't make much sense if you don't know what a quaternion is. The mathmatical explanation is complex and I've stopped caring about it. If you remember complex numbers from high school, then I'll warn you beforehand that quaternions are much much wierder. A quaternion is a 4 dimensional number. Mind you, I mean a 4 dimensional number, not a vector of 4 elements. For comparison, a complex number is two dimensional. That's why I tell you that quaternions are even wierder. A search on Wikipedia will give a brief explanation of the math involved. Be sure to have a large pot of coffee ready first. Oh, and caution: serious dangers to your mental health are ahead! For 3D game development, however, it is useful to simply think of a quaternion as a rotation about an arbitrary axis. That is, a single rotation around a single arbitrary axis. Compare that to Euler angles (your x rotation, y rotation, and z rotation) where you have three rotations around three fixed axes. The "phenomena where rotation matrices can cancel each other out" is known as gimbal lock and is actually a trait of the Euler angles used to construct those matrices, not matrices themselves. A matrix, as used in games, just defines a mapping between two coordinate spaces. In my example, there were two pieces of information that I needed to track. The ship's location and its orientation. Tracking its location was easy enough. I did that with a vector. I then had four main choices about how to store its orientation: A set of Euler angles (an x rotation, a y rotation, and a z rotation) A vector pointing in the proper direction A matrix A quaternion The Euler angles, although at first blush they do exactly what I was thinking of, actually are only useful in scenarios where the rotation is restricted. The problem, as you apply each in sequence, it modifies the axis that is used for the remaining rotations. That's what can lead to gimbal lock. This can also be awkward to deal with in a case such as my example where I want to update the ship's orientation from it's perspective rather than the viewer's perspective. To explain, consider what happens if you turn the ship around to face the viewer (initialy, in case you haven't tried the example, it is facing away from the viewer). So far, so good. But now, its nose is in the opposite direction than it was before. At that point, if I pressed forward on the stick, I wanted it to nose down, just as it would if it had been facing in the original direction (so that the nose would go down and the tail would go up). Only, with Euler angles, accomplishing that isn't straight forward as you would at first hope. To understand why, consider when the ship has nosed down 45 degrees. To get the desired behavior when the ship was facing in its original direction, the Euler angles would be 0 degrees for the yaw and 45 degrees for the pitch. However, if we're applying the yaw rotation before the pitch rotation, then when the ship is facing the viewer, then those angles become 180 degrees for the yaw and -45 degrees for the pitch. Why Because we are still rotating it around the original x axis (the viewer or world's x axis), not its own x axis. It's even more awkward when you aren't working in 90 degree increments (though, 90 degree angles are also a part of what leads to gimbal lock). Still, working around this isn't too hard to accomplish. The key is rotating the set of axis used to update the ships orientation. But, now we're talking about rotating around an arbitrary axis rather than one of the three fixed ones. To do that is going to require the use of either a quaternion or a matrix. Moving on, I could also have stored the ship's location as a vector pointing in the proper direction. Because I wanted to be also be able to roll, however, a simple vector wasn't going to work. I could have stored both a vector describing the direction the nose was pointed and a value that represented that roll, but updating that would again be difficult. I would have to translate it to some other method first and then back again. I mention the vector as an option, however, because it is sometimes a convenient way to store an object's orientation. An example where it can be useful is a third person camera. The thing that makes it useful there is that we typically want to keep the camera's up direction the same as the world's up direction. As a bonus, a vector can store distance as well as direction. Still, it wasn't suited to this application. The third option was a matrix. Make no mistake, a single matrix can completely store an object's orientation and position. And, through some matrix magic, it is possible to work around the scenario I described before about wanting to update the ship's orientation relative to its own orienation rather than the viewer's. However, regarding storage, the matrix takes 16 elements as opposed to a vector and quaternion (the vector for location and the quaternion for orientation), which combined take only seven (three for the vector and four for the quaternion). And, regarding updating the ship's orientation, updating that information when its stored quaternion takes far fewer operations than a matrix. This is in part because the quaternion has fewer elements and in part because you don't have to perform an intial step where you modify the rotation matrix to be oriented correctly before applying it to your object. Make no mistake, though... matrices are powerful. They can not only perform the rotation and translation being discussed, but scaling, projection, and a variety of other operations. What's more is that multiple matrices can be combined into a single matrix that does all the operations of a series of matrices. However, as powerful as they are, quaternions are more convenient for my example. So, that leaves us with the quaternion. As I said, the quaternion is a wierd beast. I'm not going to pretend to understand it. The following are some traits of quaternions worth knowing, however: Quaternions can fully represent the orientation of an object in 3D space (much like the directional vector and a rotation described before, although it can't represent the magnitude) Quaternions can also represent a rotation around any axis in 3D space (not just the X, Y, and Z axis like euler rotations) If you multiple a quaternion representing an object's orientation by a quaternion reprsenting a rotation, the coordinate system used in to define the axis of rotation is the rotational quaternion is from the object's space (it is defined by the object's orientation) If you multiplly quaternions representing a series of rotations together (in order), then the resulting quaternion is able to apply those rotations in one operation (much like matrices) The first three traits made them perfect for my example. I was able to fully represent the ship's orientation in a structure using four elements (a quaternion) and I was able to easily create the rotations to apply to the ship's orientation using its own coordinate system rather than the world or viewer's coordinate system. Also, by doing it this way I avoided the possibility of gimbal lock and it was faster than using a matrix to store the orientation. Of course, to display the ship on screen, I needed to use a matrix, but converting a quaternion to a matrix is a pretty simple thing to do, especially with a helper library like in XNA. Incidentally, the thing you'll hear the most about quaternions is that they avoid gimbal lock and that they can be smoothly interpolated between. But, in my case, I was just using them to store the ship's orientation and simplify the rotations. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - (Windows Only) MusicVideoDemo! After getting frustrated trying to figure out how to get my spacecraft to point at another spacecraft (I'm using quaternions for rotation, btw), I decided to tackle another problem with my game: how to play music and/or video. After chewing on this one a bit, I've created a demo that may be helpful to you. It is a work in progress so there are some problems to address. For one, when I play a video, my browser kept poping up to tell me to upgrade to WM 11. I don't know how to tell it not to do that. Another is I had to add [STAThread] just before the main function in program.cs. I don't know how that will adversely affect game performance, if any. If you just want to play music, you don't need the Windows form (or the references you need, or [STAThread]. Finally, this solution only works on Windows. That's fine by me, but maybe not for you. Time permitting I'll put together a tutorial on how I got music to work. Until then I hope I've explained things enough in the code comments. BTW, the text on the demo is faked: I'm just displaying a bitmap. You can find the demo here: http://www.spellflight.com/GameModels/MusicVideoDemo.zip Here is the readme: MusicVideoDemo Read Me Thanks for checking out this demo! I hope it will be helpful to you. I created this Windows-only demo because Microsoft's XNA 1.0 release does not contain support for playing music files like mp3 and wma, or video files such as avi and wmv. To get around the problem, I make use of the Windows Media Player. If you have Windows Media Player 10 or better, then this demo is for you. Privacy Statements Because MusicVideoDemo uses Windows Media Player, you need to be aware of your privacy rights. Keep in mind, the only thing this demo does is play music and video. Well ok, It plays a sound effect too (via XACT). If you have WM 10, this is your privacy statement: http://www.microsoft.com/windows/windowsmedia/player/10/privacy.aspx If you have WM 11 for Windows XP, this is your privacy statement: http://www.microsoft.com/windows/windowsmedia/player/11/privacy.aspx If you develop applications using the techniques I use here, you need to know about your responsibilities as developer in regards to privacy: http://go.microsoft.com/fwlink/ LinkId=29952 Credit Where Credit Is Due glass.wmv and mellow.wma come from the Windows Media Player 10 Software Development Kit: http://msdn2.microsoft.com/en-us/windowsmedia/bb190309.aspx explosion.wav comes from the Space War Starter Kit that comes from XNA 1.0, where it is called explosion1.wav. Features MusicVideoDemo demonstrates how to play music and video using Windows Media Player. Playing music works great, playing video is a bit of a kludge. Check out program.cs for the change I made there: I added [STAThread] just before the main function. I'm not sure if that will adversely affect the game. -mike mike@sbillard.org Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
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    - Any other way to buy an XNA subscription? For some reason or another my Xbox isn't accepting my credit card info (I think it may be due to the form not having an "Address line 2" field and I live in an apartment, I've checked and doublehecked all the info and the account has an ample amount of money in it), so is there any other way for me to get an XNA Creators Club subscription I tried looking to see if I could add my credit card info via Windows Live, but that didn't work out. About 60% of the reason I got this thing is because I could write programs for it, if anyone knows how to help me out I'd really appreciate it. Thanks, Johnny Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
  - 13
    - Delete a picture file after Bitmap.FromFile call. Actually, if performance matters it would be better to read the file "by hand" and use Bitmap.LockBits to fill in the data - this way you avoid having 2 copies of the image. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
  - 14
    - Blender Glenn, Thanks for taking a look. This is the model in blender: http://www.randomchaos.co.uk/XNA/blenderModel.jpg This is how it looks in my XNA project: http://www.randomchaos.co.uk/XNA/XNAModel.jpg Here is my blender project and the resulting model http://www.randomchaos.co.uk/XNA/LightCycle1.blend http://www.randomchaos.co.uk/XNA/LightCycle1.x Thanks for your time. Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
  - 15
    - Rotating triangles without using the world matrix Hi, I've only been using XNA for say, a week now Trying little things and whatnot, anywho, I was going to make a little asteroid game. Everyone knows how the game works so it's pretty much a great place to start, but unfortunately for me, I don't like using other peoples code. I always prefer to read it, re-code it and start from scratch. The problem I faced was I ran out of coffee, and couldn't figure out how to rotate a triangle, hopefully you guys will be able to help me! Just so you know, I don't want to use sprites, I want this to be 100% lines and whatnot. What I want to be able to do is independantly rotate the triangle either clockwise or anti-clockwise, without any of the other "world" changing. Forgive me for spamming, but just so you have an idea of what I'm doing I'll post my code and highlight important areas. using System; using System.Collections.Generic; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Audio; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; using Microsoft.Xna.Framework.Storage; namespace XNAShooter { public class Shooter : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; ContentManager content; GraphicsDevice device; Effect effect; VertexPositionColor[] vertices; VertexBuffer vb; IndexBuffer ib; Vector3 cameraPosition, cameraTarget; Matrix worldMatrix; Ship ship; int windowWidth, windowHeight; string windowText, effectPath; double lastTimeframe; private struct Ship { public float Agility; public float Angle; public float CurrentSpeed; public float MaxSpeed; public float MaxSpeedReverse; public Vector3 Position; public float Size; public float Thrust; }; public Shooter() { graphics = new GraphicsDeviceManager(this); content = new ContentManager(Services); } protected override void Initialize() { SetUpVars(); SetUpDevice(); SetUpCamera(); SetUpVertices(); SetUpIndices(); base.Initialize(); } private void SetUpVars() { effectPath = @"c:\effects.fx"; windowWidth = 500; windowHeight = 500; windowText = "XNA Shooter"; cameraPosition = new Vector3(0, 0, 100); cameraTarget = new Vector3(0, 0, 0); lastTimeframe = 0; ship = new Ship(); ship.Position = new Vector3(0, 0, 0); ship.Agility = 100.0f; ship.Angle = 0.0f; ship.CurrentSpeed = 0.0f; ship.MaxSpeed = 1.0f; ship.MaxSpeedReverse = -0.5f; ship.Size = 20; ship.Thrust = 0.2f; } private void SetUpDevice() { Window.Title = windowText; device = graphics.GraphicsDevice; graphics.PreferredBackBufferWidth = windowWidth; graphics.PreferredBackBufferHeight = windowHeight; graphics.IsFullScreen = false; graphics.ApplyChanges(); CompiledEffect compiledEffect = Effect.CompileEffectFromFile(effectPath, null, null, CompilerOptions.None, TargetPlatform.Windows); effect = new Effect(graphics.GraphicsDevice, compiledEffect.GetEffectCode(), CompilerOptions.None, null); } private void SetUpCamera() { float aspectRatio = this.Window.ClientBounds.Width / this.Window.ClientBounds.Height; Matrix viewMatrix = Matrix.CreateLookAt(cameraPosition, cameraTarget, new Vector3(0, 1, 0)); Matrix projMatrix = Matrix.CreatePerspectiveFieldOfView(MathHelper.PiOver4, aspectRatio, 1.0f, 150.0f); effect.Parameters["xView"].SetValue(viewMatrix); effect.Parameters["xProjection"].SetValue(projMatrix); effect.Parameters["xWorld"].SetValue(Matrix.Identity); } private void UpdateCamera() { float aspectRatio = this.Window.ClientBounds.Width / this.Window.ClientBounds.Height; Matrix viewMatrix = Matrix.CreateLookAt(cameraPosition, cameraTarget, new Vector3(0, 1, 0)); Matrix projMatrix = Matrix.CreatePerspectiveFieldOfView(MathHelper.PiOver4, aspectRatio, 1.0f, 150.0f); effect.Parameters["xView"].SetValue(viewMatrix); effect.Parameters["xProjection"].SetValue(projMatrix); effect.Parameters["xWorld"].SetValue(worldMatrix); } private void SetUpVertices() { vertices = new VertexPositionColor[3]; float size = (ship.Size / 10); vertices[0].Position = new Vector3((size / 2), size, 0f); vertices[0].Color = Color.White; vertices[1].Position = new Vector3(size, 0f, 0f); vertices[1].Color = Color.White; vertices[2].Position = new Vector3(0f, 0f, 0f); vertices[2].Color = Color.White; int verticesSize = sizeof(float) * 4 * 3; vb = new VertexBuffer(device, verticesSize, ResourceUsage.WriteOnly, ResourceManagementMode.Automatic); vb.SetData(vertices); } private void SetUpIndices() { short[] indices = new short[3] { 0,1,2 }; ib = new IndexBuffer(device, typeof(short), 3, ResourceUsage.WriteOnly, ResourceManagementMode.Automatic); ib.SetData(indices); } protected override void LoadGraphicsContent(bool loadAllContent) { if (loadAllContent) { } } protected override void UnloadGraphicsContent(bool unloadAllContent) { if (unloadAllContent == true) { content.Unload(); } } protected override void Update(GameTime gameTime) { ProcessKeyboard(gameTime); UpdateWorldMatrix(gameTime); base.Update(gameTime); } private void ProcessKeyboard(GameTime gameTime) { KeyboardState keyboard = Keyboard.GetState(); double total = gameTime.TotalRealTime.TotalMilliseconds; double elapsed = total - lastTimeframe; if (elapsed > ship.Agility) { lastTimeframe = total; if (keyboard.IsKeyDown(Keys.W)) { float speed = ship.CurrentSpeed + ship.Thrust; if (speed > ship.MaxSpeed) ship.CurrentSpeed = ship.MaxSpeed; else ship.CurrentSpeed = speed; } else if (keyboard.IsKeyDown(Keys.S)) { float speed = ship.CurrentSpeed - ship.Thrust; if (speed < ship.MaxSpeedReverse) ship.CurrentSpeed = ship.MaxSpeedReverse; else ship.CurrentSpeed = speed; } else { float thrustModifier = (ship.Thrust / 100); float slowModifier = (ship.Thrust - (thrustModifier * ship.Size)) / 3.5f; float speed; if (ship.CurrentSpeed > 0) { speed = ship.CurrentSpeed - slowModifier; if (speed < 0) ship.CurrentSpeed = 0; else ship.CurrentSpeed = speed; } else { speed = ship.CurrentSpeed + slowModifier; if (speed > 0) ship.CurrentSpeed = 0; else ship.CurrentSpeed = speed; } } if (keyboard.IsKeyDown(Keys.A)) { ship.Angle += ship.Thrust; } else if (keyboard.IsKeyDown(Keys.D)) { ship.Angle -= ship.Thrust; } } } private void UpdateWorldMatrix(GameTime gameTime) { if (ship.CurrentSpeed > 0) ship.Position.Y += ship.CurrentSpeed; else ship.Position.Y += ship.CurrentSpeed; worldMatrix = Matrix.CreateTranslation(ship.Position); //worldMatrix += Matrix.CreateFromAxisAngle(new Vector3(0, 0, 0), ship.Angle); cameraPosition = new Vector3(0, ship.Angle, 100); UpdateCamera(); } protected override void Draw(GameTime gameTime) { device.Clear(Color.Black); device.RenderState.FillMode = FillMode.WireFrame; effect.CurrentTechnique = effect.Techniques["Colored"]; effect.Parameters["xWorld"].SetValue(worldMatrix); effect.Begin(); foreach (EffectPass pass in effect.CurrentTechnique.Passes) { pass.Begin(); DrawShip(); pass.End(); } effect.End(); base.Draw(gameTime); } private void DrawShip() { device.Vertices[0].SetSource(vb, 0, VertexPositionColor.SizeInBytes); device.Indices = ib; device.VertexDeclaration = new VertexDeclaration(device, VertexPositionColor.VertexElements); device.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 4, 0, 2); } } } Ok, now I know it looks bad but I just threw it together. I have since spent my time writing a little library to simplify alot of the above, basically, i want the angle to be modified when either A or D is pressed, and on the update - it rotates the triangle to face that direction, so to speak. The italic code is an attempt that didnt work, you can ignore it :) This is greatly apprechiated btw, Thanks! Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.
  - 16
    - Making XNA/Managed code secure Joel Martinez wrote: Is obfuscation not good enough for you No, see http://www.remotesoft.com/salamander/ additionally, my whole point is not that it isn't possible to make the code more secure (obviously third party vendors are making money off it) my point is why isn't microsoft shipping a product integrated with visual studio pro or orcas that will secure code. Visual studio is already expensive enough, it should be my whole solution, i shouldn't have to go buy an obfuscator, protector, and all this other junk just to have safe code. I've never had to pay extra to get locks installed on a car or house... Tag: XNA Game Studio Express Animated Sprite - the MSDN example Game Technologies: DirectX, XNA, XACT, etc.

LamptonWorm

Hi,

With regards to this article, does anyone have the graphic they are loading in or a similar example I whipped up a simple 48x16 .png anim strip but when I use the AnimatedSprite class, it only shows one frame - the first, then blank, then frame 1 and so on, not the other 3 frames.

I'm sure it's something simple I'm missing! I've entered the frame total as 3 by the way as I have 3 frames in that image.

Cheers,
Dylan.

Re: XNA Game Studio Express Animated Sprite - the MSDN example

Joel Martinez

I would put a breakpoint in the DrawFrame method and see what values are being calculated for the "sourcerect" every frame. Do they fall within the bounds of your texture \

I would also potentially look at the UpdateFrame method ... are you calling this method and passing in "(float)gameTime.ElapsedGameTime.TotalSeconds"

Re: XNA Game Studio Express Animated Sprite - the MSDN example

ProfEclipse

Also note that there is a bug in the article. The line:

Frame = Frame % (framecount - 1);

should be:

Frame = Frame % framecount;

With the "- 1", if framecount is 4, then you would get a value between 0 and 2, not the desired 0 and 3.

Re: XNA Game Studio Express Animated Sprite - the MSDN example

LamptonWorm

Thanks both.

It was probably just the end of a long day, but I was still a bit confused at how rectangle works - you can probably help me there too ;) - is the placement and size of the rectangle different to the content pasted 'into' the rectangle or can you do both in a single command

e.g. set up my drawing area to start at 0,0 and set its size to 16,16 - then using my image take a snap from say 16,0 to 32,16, and paste that at 0,0. Hope that makes sense, at least my head it appears to - hmm!

Cheers :)

Re: XNA Game Studio Express Animated Sprite - the MSDN example

ProfEclipse

Yes, that will work. The source rectangle determines the contents of the image to display, and the destination rectangle determines the location and size of the displayed image. And remember, a rectangle is defined as it's origin and size, not it's top-left and lower-right corners. So, in your example case, destination would be (0,0,16,16), and source would be (16,0,16,16).

Re: XNA Game Studio Express Animated Sprite - the MSDN example

LamptonWorm

Thanks.