Hi! i created a 3d model in softimage XSI, painted some vertex colors on it and exportet it as .x model. How can I now use these vertex colors in a HLSL programmed vertex shader?? I tried all the Vertex Shader Inpout Semantics - but it didn't work . . . can someone help me? thx!

The right semantic is COLOR0-COLORn; depending on how the shader is implemented. I don't know if the X-format supports any kind of vertex declaration, however.

Greetz,

Illco

hi Illco!
.x should support vertex colors . . . but i don't know how to use them . . .

when i want to load them with this shader:


////VertexShader:

float4 view_position;
float4 light0;
float4x4 view_proj_matrix;

struct VS_OUTPUT
{
float4 Pos : POSITION;
float3 View : TEXCOORD0;
float3 Normal: TEXCOORD1;
float3 Light1: TEXCOORD2;
float4 vertexcol: COLOR0;
float3 gradient: TEXCOORD5;
};
VS_OUTPUT main( float4 inPos : POSITION,
float3 inNorm : NORMAL,
float4 Col: COLOR )
{
VS_OUTPUT Out = (VS_OUTPUT) 0;

// Output transformed vertex position:
Out.Pos = mul( view_proj_matrix, inPos );

Out.Normal = inNorm;

// Compute the view vector:
Out.View = normalize( view_position - inPos );

// Compute light vector
Out.Light1 = normalize(light0 - inPos); // Light 1

// create gradient
Out.gradient = inPos.y;

//create vertexcolormap
Out.vertexcol=Col;

return Out;
}


/////Pixel Shader

float4 color1;
float4 color2;
float4 main( float3 View: TEXCOORD0,
float3 Normal: TEXCOORD1,
float3 Light1: TEXCOORD2,
float4 vertexcol: COLOR0,
float3 gradient: TEXCOORD5 ) : COLOR
{
// Normalize input normal vector:
float3 norm = normalize (Normal);

float incidence = 1-dot (norm, normalize(View));

float lighting = (dot (normalize (Light1), norm) * 0.5 + 0.5)-0.45;

float4 normals = float4(norm,0.0);
float4 viewdirect = float4(View, 0.0);
float4 Gradient = (float4(gradient,0.0)/4+1)/2;


//return lighting;
//return lerp(color2, color1, Gradient);
//return lerp(color2, color1, Gradient)+lighting;
//return incidence;
return vertexcol;
}




then i get that:

http://neo.cycovery.com/skullcolor.jpg

Maybe try a simpler shader first -- one which just puts on the vertex color and nothing else. Then you can see if the color component is transferred well. With DX a shader 'simple.fx' comes, which pretty much shows how this is done. Then use a graphical editor like EffectEdit (DX) or FX Composer (NVidia); this allows you to see the difference each change makes to the visuals.

Greetz,

Illco

My kneejerk reaction is that

Quote:float4 Col: COLOR )

(from the vertex shader function declaration)

should be

Quote:float4 Col: COLOR0 )

so that leads me to another question about those input output Semantics!

What is the difference between COLOR and COLORn ? or TEXCOORD and TEXCOORDn ?

I found out, that the first uv coordinates from a model for example are stored in TEXCOORD0 . . . but when i generate an vertex output semantic which refers to TEXCOORD0 - what happens then? will the uv coordinates of the 3d model get overrided? what if I don't output a TEXCOORD0? can i then use the original uv coordinates of the model direclty in the Pixelshader?

and what means the :COLOR in this construction:


float4 main( float3 View: TEXCOORD3,
float3 Normal: TEXCOORD1,
float3 Light1: TEXCOORD2,
float4 vertexcol: COLOR0,
float3 gradient: TEXCOORD5,
float2 uv: TEXCOORD0 ) : COLOR
{
//mainfunction of the pixelshader
}