XNA L04–Primitives, IndexBuffer and VertexBuffer
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This document discusses drawing 3D primitives and using vertex and index buffers in XNA game development. It begins with an overview of different primitive types like points, lines, and triangles. It then covers drawing triangles by defining vertex positions and colors. Next, it demonstrates creating a rotating tetrahedron using triangle lists. The document concludes by explaining how to create an icosahedron mesh using vertex and index buffers to store vertex data more efficiently for rendering. Key steps include generating vertex and index data, creating vertex and index buffers, and drawing indexed triangles.
![Drawing Triangles
• Global Scope
SpriteBatch spriteBatch;
VertexPositionColor[] vertices;
BasicEffect basicEffect;
Matrix world = Matrix.CreateTranslation(0, 0, 0);
Matrix view = Matrix.CreateLookAt(
new Vector3(0, 0, 3),
new Vector3(0, 0, 0),
new Vector3(0, 1, 0));
Matrix projection = Matrix.CreatePerspectiveFieldOfView(
MathHelper.ToRadians(45),
800f / 600f,
0.01f,
100f);](https://image.slidesharecdn.com/xnal02primitivesindexbufferandvertexbuffer-140211151953-phpapp01/85/XNA-L04-Primitives-IndexBuffer-and-VertexBuffer-11-320.jpg)
![Drawing Triangles
SpriteBatch spriteBatch;
VertexPositionColor[] vertices;
BasicEffect basicEffect;
Matrix world = Matrix.CreateTranslation(0, 0, 0);
Matrix view = Matrix.CreateLookAt(
new Vector3(0, 0, 3),
new Vector3(0, 0, 0),
new Vector3(0, 1, 0));
Matrix projection = Matrix.CreatePerspectiveFieldOfView(
MathHelper.ToRadians(45),
800f / 600f,
0.01f,
100f);](https://image.slidesharecdn.com/xnal02primitivesindexbufferandvertexbuffer-140211151953-phpapp01/85/XNA-L04-Primitives-IndexBuffer-and-VertexBuffer-12-320.jpg)
![Drawing Triangles
• LoadContent()
protected override void LoadContent()
{
// Create a new SpriteBatch, which can be used to draw textures.
spriteBatch = new SpriteBatch(GraphicsDevice);
basicEffect = new BasicEffect(GraphicsDevice);
vertices = new VertexPositionColor[3];
vertices[0] = new VertexPositionColor(new Vector3(0, 1, 0), Color.Red);
vertices[1] = new VertexPositionColor(new Vector3(+0.5f, 0, 0), Color.Green);
vertices[2] = new VertexPositionColor(new Vector3(-0.5f, 0, 0), Color.Blue);
}](https://image.slidesharecdn.com/xnal02primitivesindexbufferandvertexbuffer-140211151953-phpapp01/85/XNA-L04-Primitives-IndexBuffer-and-VertexBuffer-13-320.jpg)
![Drawing Triangles
• LoadContent()
protected override void LoadContent()
{
// Create a new SpriteBatch, which can be used to draw textures.
spriteBatch = new SpriteBatch(GraphicsDevice);
basicEffect = new BasicEffect(GraphicsDevice);
vertices = new VertexPositionColor[3];
vertices[0] = new VertexPositionColor(new Vector3(0, 1, 0), Color.Red);
vertices[1] = new VertexPositionColor(new Vector3(+0.5f, 0, 0), Color.Green);
vertices[2] = new VertexPositionColor(new Vector3(-0.5f, 0, 0), Color.Blue);
}](https://image.slidesharecdn.com/xnal02primitivesindexbufferandvertexbuffer-140211151953-phpapp01/85/XNA-L04-Primitives-IndexBuffer-and-VertexBuffer-14-320.jpg)
![Drawing Triangles – Simple Rotation
• How to do it with a simple rotation?!
vertices = new VertexPositionColor[12];
vertices[0] = new VertexPositionColor(new Vector3(0.000f, 1.000f, 0.000f), Color.Red);
vertices[1] = new VertexPositionColor(new Vector3(-0.816f, -0.333f, -0.471f), Color.Blue);
vertices[2] = new VertexPositionColor(new Vector3(0.000f, -0.333f, 0.943f), Color.Green);
vertices[3] = new VertexPositionColor(new Vector3(0.000f, 1.000f, 0.000f), Color.Red);
vertices[4] = new VertexPositionColor(new Vector3(0.816f, -0.333f, -0.471f), Color.Yellow);
vertices[5] = new VertexPositionColor(new Vector3(-0.816f, -0.333f, -0.471f), Color.Blue);
vertices[6] = new VertexPositionColor(new Vector3(0.000f, -0.333f, 0.943f), Color.Green);
vertices[7] = new VertexPositionColor(new Vector3(0.816f, -0.333f, -0.471f), Color.Yellow);
vertices[8] = new VertexPositionColor(new Vector3(0.000f, 1.000f, 0.000f), Color.Red);
vertices[9] = new VertexPositionColor(new Vector3(-0.816f, -0.333f, -0.471f), Color.Blue);
vertices[10]= new VertexPositionColor(new Vector3(0.816f, -0.333f, -0.471f), Color.Yellow);
vertices[11] = new VertexPositionColor(new Vector3(0.000f, -0.333f, 0.943f), Color.Green);
VertexPositionColor[] vertices;](https://image.slidesharecdn.com/xnal02primitivesindexbufferandvertexbuffer-140211151953-phpapp01/85/XNA-L04-Primitives-IndexBuffer-and-VertexBuffer-29-320.jpg)
![Index And Vertex Buffers – The Creating of
• Creating the Necessary Variables
VertexBuffer vertexBuffer;
IndexBuffer indexBuffer;
VertexPositionColor[] vertices;](https://image.slidesharecdn.com/xnal02primitivesindexbufferandvertexbuffer-140211151953-phpapp01/85/XNA-L04-Primitives-IndexBuffer-and-VertexBuffer-51-320.jpg)
![Index And Vertex Buffers – The Creating of
• Creating the Necessary Variables
VertexBuffer vertexBuffer;
IndexBuffer indexBuffer;
VertexPositionColor[] vertices; // Needed in a global scope or not?](https://image.slidesharecdn.com/xnal02primitivesindexbufferandvertexbuffer-140211151953-phpapp01/85/XNA-L04-Primitives-IndexBuffer-and-VertexBuffer-52-320.jpg)
![Index And Vertex Buffers – The Creating of
• Creating the Necessary Variables
VertexBuffer vertexBuffer;
IndexBuffer indexBuffer;
VertexPositionColor[] vertices; // Needed in a global scope or not?](https://image.slidesharecdn.com/xnal02primitivesindexbufferandvertexbuffer-140211151953-phpapp01/85/XNA-L04-Primitives-IndexBuffer-and-VertexBuffer-53-320.jpg)
![Index And Vertex Buffers – The Creating of
• In LoadContent()
VertexPositionColor[] vertexArray = new VertexPositionColor[12];
// vertex position and color information for icosahedron
vertexArray[0] = new VertexPositionColor(new Vector3(-0.26286500f, 0.0000000f, 0.42532500f), Color.Red);
//…..
vertexArray[11]= new VertexPositionColor(new Vector3(-0.42532500f, -0.26286500f, 0.0000000f),Color.Crimson);
// Set up the vertex buffer
vertexBuffer = new VertexBuffer( graphics.GraphicsDevice,
typeof(VertexPositionColor),
vertexArray.Length,
BufferUsage.WriteOnly);
vertexBuffer.SetData(vertexArray);
short[] indices = new short[60];
indices[0] = 0; indices[1] = 6; indices[2] = 1;
//…
indices[57] = 9; indices[58] = 11; indices[59] = 0;
indexBuffer = new IndexBuffer(graphics.GraphicsDevice, typeof(short), indices.Length, BufferUsage.WriteOnly);
indexBuffer.SetData(indices);](https://image.slidesharecdn.com/xnal02primitivesindexbufferandvertexbuffer-140211151953-phpapp01/85/XNA-L04-Primitives-IndexBuffer-and-VertexBuffer-54-320.jpg)
XNA L04–Primitives, IndexBuffer and VertexBuffer
- 1. Mohammad Shaker mohammadshaker.com @ZGTRShaker 2011, 2012, 2013, 2014 XNA Game Development L04 – Primitives, IndexBuffer and VertexBuffer
- 2. 3D World
- 3. 3D World
- 4. 3D World
- 5. Primitives • 1 - Drawing Triangles • 2 - A Little Practice • 3 - Index and Vertex Buffers • 4 - Primitive Types
- 6. Primitives
- 8. Drawing Triangles What do we need to draw?!
- 11. Drawing Triangles • Global Scope SpriteBatch spriteBatch; VertexPositionColor[] vertices; BasicEffect basicEffect; Matrix world = Matrix.CreateTranslation(0, 0, 0); Matrix view = Matrix.CreateLookAt( new Vector3(0, 0, 3), new Vector3(0, 0, 0), new Vector3(0, 1, 0)); Matrix projection = Matrix.CreatePerspectiveFieldOfView( MathHelper.ToRadians(45), 800f / 600f, 0.01f, 100f);
- 12. Drawing Triangles SpriteBatch spriteBatch; VertexPositionColor[] vertices; BasicEffect basicEffect; Matrix world = Matrix.CreateTranslation(0, 0, 0); Matrix view = Matrix.CreateLookAt( new Vector3(0, 0, 3), new Vector3(0, 0, 0), new Vector3(0, 1, 0)); Matrix projection = Matrix.CreatePerspectiveFieldOfView( MathHelper.ToRadians(45), 800f / 600f, 0.01f, 100f);
- 13. Drawing Triangles • LoadContent() protected override void LoadContent() { // Create a new SpriteBatch, which can be used to draw textures. spriteBatch = new SpriteBatch(GraphicsDevice); basicEffect = new BasicEffect(GraphicsDevice); vertices = new VertexPositionColor[3]; vertices[0] = new VertexPositionColor(new Vector3(0, 1, 0), Color.Red); vertices[1] = new VertexPositionColor(new Vector3(+0.5f, 0, 0), Color.Green); vertices[2] = new VertexPositionColor(new Vector3(-0.5f, 0, 0), Color.Blue); }
- 14. Drawing Triangles • LoadContent() protected override void LoadContent() { // Create a new SpriteBatch, which can be used to draw textures. spriteBatch = new SpriteBatch(GraphicsDevice); basicEffect = new BasicEffect(GraphicsDevice); vertices = new VertexPositionColor[3]; vertices[0] = new VertexPositionColor(new Vector3(0, 1, 0), Color.Red); vertices[1] = new VertexPositionColor(new Vector3(+0.5f, 0, 0), Color.Green); vertices[2] = new VertexPositionColor(new Vector3(-0.5f, 0, 0), Color.Blue); }
- 15. Drawing Triangles • Draw() protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); basicEffect.World = world; basicEffect.View = view; basicEffect.Projection = projection; basicEffect.VertexColorEnabled = true; foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.DrawUserPrimitives<VertexPositionColor> (PrimitiveType.TriangleList, vertices, 0, 1); } base.Draw(gameTime); }
- 19. Different Primitive Types • PrimitiveType.Points • PrimitiveType.LineList • PrimitiveType.LineStrip • PrimitiveType.TriangleList • PrimitiveType.TriangleStrip • PrimitiveType.TriangleFan
- 24. Drawing Triangles • Using TrianglesList • App2-Tetrahedron-TriangleList
- 25. Drawing Triangles • How to do it with a simple rotation?!
- 26. Drawing Triangles • How to do it with a simple rotation?! • First, What’s that 3D Object is?! Tetrahedron! (Faces: 4, Vertices: 12)
- 27. Drawing Triangles • How to do it with a simple rotation?! • First, What’s that 3D Object is?! Tetrahedron! (Faces: 4, Vertices: 12(Each one at a time or a one shot?!))
- 28. Drawing Triangles • How to do it with a simple rotation?! • First, What’s that 3D Object is?! Tetrahedron! (Faces: 4, Vertices: 12(use TriangleList))
- 29. Drawing Triangles – Simple Rotation • How to do it with a simple rotation?! vertices = new VertexPositionColor[12]; vertices[0] = new VertexPositionColor(new Vector3(0.000f, 1.000f, 0.000f), Color.Red); vertices[1] = new VertexPositionColor(new Vector3(-0.816f, -0.333f, -0.471f), Color.Blue); vertices[2] = new VertexPositionColor(new Vector3(0.000f, -0.333f, 0.943f), Color.Green); vertices[3] = new VertexPositionColor(new Vector3(0.000f, 1.000f, 0.000f), Color.Red); vertices[4] = new VertexPositionColor(new Vector3(0.816f, -0.333f, -0.471f), Color.Yellow); vertices[5] = new VertexPositionColor(new Vector3(-0.816f, -0.333f, -0.471f), Color.Blue); vertices[6] = new VertexPositionColor(new Vector3(0.000f, -0.333f, 0.943f), Color.Green); vertices[7] = new VertexPositionColor(new Vector3(0.816f, -0.333f, -0.471f), Color.Yellow); vertices[8] = new VertexPositionColor(new Vector3(0.000f, 1.000f, 0.000f), Color.Red); vertices[9] = new VertexPositionColor(new Vector3(-0.816f, -0.333f, -0.471f), Color.Blue); vertices[10]= new VertexPositionColor(new Vector3(0.816f, -0.333f, -0.471f), Color.Yellow); vertices[11] = new VertexPositionColor(new Vector3(0.000f, -0.333f, 0.943f), Color.Green); VertexPositionColor[] vertices;
- 30. Drawing Triangles – Simple Rotation protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); basicEffect.World = world; basicEffect.View = view; basicEffect.Projection = projection; basicEffect.VertexColorEnabled = true; foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.DrawUserPrimitives(PrimitiveType.TriangleList, vertices, 0, 4); } base.Draw(gameTime); }
- 31. Drawing Triangles – Simple Rotation protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); basicEffect.World = world; basicEffect.View = view; basicEffect.Projection = projection; basicEffect.VertexColorEnabled = true; foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.DrawUserPrimitives(PrimitiveType.TriangleList, vertices, 0, 4); } base.Draw(gameTime); }
- 32. Drawing Triangles – Simple Rotation protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); basicEffect.World = world; basicEffect.View = view; basicEffect.Projection = projection; basicEffect.VertexColorEnabled = true; foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.DrawUserPrimitives(PrimitiveType.TriangleList, vertices, 0, 4); } base.Draw(gameTime); }
- 33. Drawing Triangles – Simple Rotation protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); basicEffect.World = world; basicEffect.View = view; basicEffect.Projection = projection; basicEffect.VertexColorEnabled = true; foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.DrawUserPrimitives(PrimitiveType.TriangleList, vertices, 0, 4); } base.Draw(gameTime); }
- 34. Drawing Triangles – Rotation Logic
- 35. Drawing Triangles – Rotation Logic Matrices and Transformations
- 36. Drawing Triangles • Using TrianglesList • App3-TriangleList
- 37. Different Primitive Types • Changing last tutorial PrimitiveType to LineList will result in • “App5-VertexBuffer-LineList”
- 38. Index And Vertex Buffers
- 39. Index And Vertex Buffers The Concept
- 40. Index And Vertex Buffers • Effectively store our data • Greatly reduce the amount of data that needs to be send over to the graphics device – speed up our applications a looooooooooot! • The only way to store your data
- 41. Index And Vertex Buffers • Look at this,
- 42. Index And Vertex Buffers True oder false? • Look at this,
- 43. Index And Vertex Buffers True oder false? • Look at this,
- 44. Index And Vertex Buffers
- 45. Index And Vertex Buffers
- 46. Index And Vertex Buffers
- 47. Index And Vertex Buffers
- 48. Index And Vertex Buffers – The Creating of • An Icosahedron
- 49. Index And Vertex Buffers – The Creating of • An Icosahedron • “App4-VertexBuffer”
- 50. Index And Vertex Buffers – The Creating of • Creating the Necessary Variables VertexBuffer vertexBuffer; IndexBuffer indexBuffer;
- 51. Index And Vertex Buffers – The Creating of • Creating the Necessary Variables VertexBuffer vertexBuffer; IndexBuffer indexBuffer; VertexPositionColor[] vertices;
- 52. Index And Vertex Buffers – The Creating of • Creating the Necessary Variables VertexBuffer vertexBuffer; IndexBuffer indexBuffer; VertexPositionColor[] vertices; // Needed in a global scope or not?
- 53. Index And Vertex Buffers – The Creating of • Creating the Necessary Variables VertexBuffer vertexBuffer; IndexBuffer indexBuffer; VertexPositionColor[] vertices; // Needed in a global scope or not?
- 54. Index And Vertex Buffers – The Creating of • In LoadContent() VertexPositionColor[] vertexArray = new VertexPositionColor[12]; // vertex position and color information for icosahedron vertexArray[0] = new VertexPositionColor(new Vector3(-0.26286500f, 0.0000000f, 0.42532500f), Color.Red); //….. vertexArray[11]= new VertexPositionColor(new Vector3(-0.42532500f, -0.26286500f, 0.0000000f),Color.Crimson); // Set up the vertex buffer vertexBuffer = new VertexBuffer( graphics.GraphicsDevice, typeof(VertexPositionColor), vertexArray.Length, BufferUsage.WriteOnly); vertexBuffer.SetData(vertexArray); short[] indices = new short[60]; indices[0] = 0; indices[1] = 6; indices[2] = 1; //… indices[57] = 9; indices[58] = 11; indices[59] = 0; indexBuffer = new IndexBuffer(graphics.GraphicsDevice, typeof(short), indices.Length, BufferUsage.WriteOnly); indexBuffer.SetData(indices);
- 55. Index And Vertex Buffers • In Draw() Method foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.SetVertexBuffer(vertexBuffer); graphics.GraphicsDevice.Indices = indexBuffer; graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 12, 0, 20); }
- 56. Index And Vertex Buffers • In Draw() Method foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.SetVertexBuffer(vertexBuffer); graphics.GraphicsDevice.Indices = indexBuffer; graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 12, 0, 20); }
- 57. Index And Vertex Buffers • In Draw() Method foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.SetVertexBuffer(vertexBuffer); graphics.GraphicsDevice.Indices = indexBuffer; graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 12, 0, 20); }
- 58. Index And Vertex Buffers • In Draw() Method foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.SetVertexBuffer(vertexBuffer); graphics.GraphicsDevice.Indices = indexBuffer; graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 12, 0, 20); }
- 59. Index And Vertex Buffers • In Draw() Method foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.SetVertexBuffer(vertexBuffer); graphics.GraphicsDevice.Indices = indexBuffer; graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 12, 0, 20); }
- 60. Index And Vertex Buffers • In Draw() Method foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.SetVertexBuffer(vertexBuffer); graphics.GraphicsDevice.Indices = indexBuffer; graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 12, 0, 20); }
- 61. Index And Vertex Buffers • In Draw() Method foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.SetVertexBuffer(vertexBuffer); graphics.GraphicsDevice.Indices = indexBuffer; graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 12, 0, 20); }
- 63. Index And Vertex Buffers • In Draw() Method foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.SetVertexBuffer(vertexBuffer); graphics.GraphicsDevice.Indices = indexBuffer; graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 12, 0, 20); }
- 64. Index And Vertex Buffers • In Draw() Method foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.SetVertexBuffer(vertexBuffer); graphics.GraphicsDevice.Indices = indexBuffer; graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 12, 0, 20); }
- 65. Index And Vertex Buffers • In Draw() Method foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.SetVertexBuffer(vertexBuffer); graphics.GraphicsDevice.Indices = indexBuffer; graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 12, 0, 20); }
- 66. Index And Vertex Buffers • In Draw() Method foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.SetVertexBuffer(vertexBuffer); graphics.GraphicsDevice.Indices = indexBuffer; graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 12, 0, 20); }
- 67. Index And Vertex Buffers • In Draw() Method foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.SetVertexBuffer(vertexBuffer); graphics.GraphicsDevice.Indices = indexBuffer; graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 12, 0, 20); }
- 68. Index And Vertex Buffers • In Draw() Method foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.SetVertexBuffer(vertexBuffer); graphics.GraphicsDevice.Indices = indexBuffer; graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 12, 0, 20); }
- 69. Index And Vertex Buffers • In Draw() Method foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.SetVertexBuffer(vertexBuffer); graphics.GraphicsDevice.Indices = indexBuffer; graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 12, 0, 20); }
- 70. Index And Vertex Buffers • An Icosahedron at last has been built!