Weird hlsl shader compilation problem

[Erelas]

Hello there,

I'm currently working on a hardware skinning shader in my project and I have it working, but only with a weird limitation.

This is the working shader:

Code: Select all

float4x4 World;
float4x4 View;  
float4x4 Projection;
float4x4 WorldViewProjection;
 
// max. number of bones
static const int MAX_MATRICES = 64;
float4x4 BonesMatrix[MAX_MATRICES];
 
//  input for the vertex shader
struct VS_INPUT
{
    float4 Position     : POSITION0;
    float4 Normal       : NORMAL0;
    float4 Color        : COLOR0;
    float2 TexCoord     : TEXCOORD0;
    float4 BlendIndices : BLENDINDICES0;
    float4 BlendWeights : BLENDWEIGHT0;
    float4 Tangent      : TANGENT0;
    float4 Binormal     : BINORMAL0;    
};
 
struct VS_OUTPUT
{
    float4 Position  : POSITION0;
    float4 Color     : COLOR0;
    float2 TexCoord  : TEXCOORD0;
};
 
VS_OUTPUT main(VS_INPUT input)
{
    VS_OUTPUT output = (VS_OUTPUT)0;
    output.Color = float4(0.0, 0.2, 0.4, 1);
    float4 worldPos = mul(input.Position, World);
    float4 viewPos = mul(worldPos, View);
    
    // calculate the pos/normal using the "normal" weights and accumulate the weights to calculate the last weight
    int NumBones = 4;
    int BoneIndex = 1;
    float Weight = 0;
    float LastWeight = 1;
    float4 Position = 0;
    
    // Blend between the weighted bone matrices.
    for(int iBone = 0; iBone < NumBones -1; iBone++)
    {   
    
        BoneIndex = int(input.BlendIndices[iBone]);
        Weight = float(input.BlendWeights[iBone]);
        LastWeight = LastWeight - Weight;
        
        if (BoneIndex < 61)
        {   
            float4 difference = mul(input.Position, BonesMatrix[BoneIndex]) * Weight;
            Position.xyz += difference.xyz;
        }
    }
    
    BoneIndex = int(input.BlendIndices[NumBones-1]);
    if (BoneIndex < 61)
    {
        float4 difference = mul(input.Position, BonesMatrix[BoneIndex]) * LastWeight;
        Position.xyz += difference.xyz;
    }
 
    output.Position = mul(float4(Position.xyz, 1.0f), WorldViewProjection);
    output.Color.rgba = input.Color;
    output.TexCoord = input.TexCoord;
 
    return output;
}

But I want to support more bones, for example 128 bones. So I need this check gone:

Code: Select all

...
if(BoneIndex < 61)
...

But when I try to run it with that change I won't get any working material and CD3D9HLSLMaterialRenderer.cpp says:
"Could not create hlsl vertex shader."

This is how I load my shader:

Code: Select all

// Setup the skin shader 
    irr::s32 material = irr::video::EMT_SOLID;
    irr::scene::ISceneManager* smgr = m_device->getSceneManager();
    irr::video::IVideoDriver* driver = m_device->getVideoDriver();
    m_callback = std::make_shared<SkinShaderCallback>();
    if (driver->queryFeature(irr::video::EVDF_VERTEX_SHADER_2_0)) {
        irr::video::IGPUProgrammingServices* gpu = driver->getGPUProgrammingServices();
        if (gpu) {
            // DirectX 9
            if (driver->getDriverType() == irr::video::EDT_DIRECT3D9) {
                material = gpu->addHighLevelShaderMaterialFromFiles("data/skin_vs.hlsl", "main", irr::video::EVST_VS_1_1, "", "", irr::video::EPST_PS_2_0, m_callback.get(), irr::video::EMT_SOLID);
            }
        }
    } 

I've also tried all manner of E_VERTEX_SHADER_TYPE to no avail.

We are using the shader-pipeline branch:
svn://svn.code.sf.net/p/irrlicht/code/branches/shader-pipeline

Thanks in advance,

Erelas

[Nadro]

This is Shader Model 3.0 limitation for uniforms, encode bone matrices into texture is better solution. You can find some info here:
http://developer.amd.com/wordpress/medi ... mation.zip (pdf included in archive)

[Erelas]

If I create the shader material using irr::video::EVST_VS_5_0, wouldn't that use Shader Model 5.0 which has no such limitation?

Thanks for the info, will check it out.

[Nadro]

No D3D9 support irr::video::EVST_VS_3_0 and lower, for newer drivers eg. OGL 3+, OGL ES2+, DX10+ irr::video::EVST_VS_X_X is unimportant. This flag should be removed in future and functionality of them should be replaced by E_GPU_SHADING_LANGUAGE variable (EGSL_DEFAULT, EGSL_ASM (for compatibility with ASM shaders in older drivers), EGSL_CG).