Hello Guys,

i have a big problem, i want to create an example for Instance Rendering, but the World Matricen dosen't work, only the Scale Informations comes to the Shader, the Translation and Rotation Values not :(

Here is my Code:

Shader:

matrix World      : WORLD;
matrix View       : VIEW;
matrix Projection : PROJECTION;

float3 DiffuseColor = {1.0f, 0.0f, 0.0f};

struct Vertex
{
 float3 Position : POSITION;
 matrix instance : INSTANCE;
};

struct Pixel
{
 float4 Position : SV_POSITION;
};

float4 TransformVertex(Vertex input)
{
 float4 objectSpace = float4(input.Position.xyz, 1.0f);
 float4 worldSpace = mul(objectSpace, (World * input.instance));
 float4 viewSpace = mul(worldSpace, View);
 float4 projectionSpace = mul(viewSpace, Projection);

 return projectionSpace;
}

Pixel vertexShader(Vertex input)
{
 Pixel result = (Pixel) 0;
 result.Position = TransformVertex(input);

 return result;
}

float4 pixelShader(Pixel input) : SV_Target0
{
 return float4(DiffuseColor.rgb, 1.0f);
}

technique11 Main
{
 pass p0
 {
  SetVertexShader(CompileShader(vs_5_0, vertexShader()));
  SetHullShader(NULL);
  SetDomainShader(NULL);
  SetGeometryShader(NULL);
  SetPixelShader(CompileShader(ps_5_0, pixelShader()));
 }
}

Initialize Shader:

            this.simpleShader = new ShaderDescription(this.deviceEngine.Device, "simpleShader", "SimpleShader", @"C:\Path\SimpleShader.fx", "fx_5_0", new[]
            {
                new InputElement("POSITION", 0, Format.R32G32B32_Float, 0, 0, InputClassification.PerVertexData, 0),
                new InputElement("INSTANCE", 0, Format.R32G32B32A32_Float, 0, 1, InputClassification.PerInstanceData, 1),
                new InputElement("INSTANCE", 1, Format.R32G32B32A32_Float, 16, 1, InputClassification.PerInstanceData, 1),
                new InputElement("INSTANCE", 2, Format.R32G32B32A32_Float, 32, 1, InputClassification.PerInstanceData, 1),
                new InputElement("INSTANCE", 3, Format.R32G32B32A32_Float, 48, 1, InputClassification.PerInstanceData, 1),
            });

Write Matrix in Buffer:

                this.device = device;

                int sizeInBytes = 64;

                int totalSizeInBytes = 1 * sizeInBytes;

                Matrix world = Matrix.Scaling(2, 1, 1) * Matrix.RotationYawPitchRoll(50, 0, 0) * Matrix.Translation(3, 0, 0);

                DataStream vertexStream = new DataStream(totalSizeInBytes, true, true);

                vertexStream.WriteRange(world.ToArray());

                vertexStream.Position = 0;

                this.buffer = new Buffer(device, vertexStream, new BufferDescription(totalSizeInBytes,
                    ResourceUsage.Default, BindFlags.VertexBuffer, CpuAccessFlags.None, ResourceOptionFlags.None, 0));

                this.bufferBinding = new VertexBufferBinding(this.buffer, sizeInBytes, 0);

DrawInstanced:

                        this.device.SetVertexBuffer(0, this.vertexBuffer.BufferBinding);
                        this.device.SetVertexBuffer(1, this.matricenBuffer.BufferBinding);
 
                        this.device.DeviceContext.InputAssembler.PrimitiveTopology = mesh.VerticesType;

                        this.Apply(mesh.Material, world, view, projection);
                        this.device.DeviceContext.DrawInstanced(mesh.Vertices.Count, 1, this.startPosition, 0);

I don't get it what i make wrong, hope you guys can help me!?

Greets

John

Hi Adam Miles,

but "mul" do only work with a float4 and a matrix, not a matrix and a matrix, for that i have the operator * !?

I want that the new World matrix is the result of the standart World matrix (Identity) and the with given matrix from my Instance Buffer.

Greets

John

Hi Adam Miles,

I had try it with "mul(World, input.Instance)" and i get an exception and I want a 4x4 matrix, not a 3x3 matrix!?

Greets

John

I don't know exactly what you mean, but here the error message!?

ps. I had checked it befor with:

float3 pos =  float3(input.instance[3][0], input.instance[3][1], input.instance[3][2]);
float4 objectSpace = float4(input.Position.xyz + pos, 1.0f);

And the result was zero (the Mesh location was 0, 0, 0), but that makes no sense, because i had wrote in the Instance Buffer my Matrix with the Translation of (3, 0, 0)!?

Greets

John

Hi Adam Miles,

sry, i thought I had wrote a comma, don't saw that still a *

Now i had wrote:

 float4 worldSpace = mul(objectSpace, mul(World, input.instance));

And the result with my Cube is horrible :(

Greets

John