Mesh Rendering - Practical Rendering and Computation with Direct3D 11 - page 395

struct VS_OUTPUT
{

float4 position : SV_Position;

float3 normal : NORMAL;

float3 light : LIGHT;

float2 tex : TEXCOORDS;

};

VS_OUTPUT VSMAIN( in VS_INPUT input )
{

VS_OUTPUT output;

// Calculate the output position of the vertex
output.position = (mul( float4( input.position, 1.0f ),
SkinMatrices[input.bone.x] )
* input.weights. x);
output.position +=(mul( float4( input.position , 1.0f ),
SkinMatrices[input.bone.y] )
* input.weights. y);
output.position += (mul( float4( input.position, 1.0f ),
SkinMatrices[input.bone.z] )
* input.weights. z);
output.position += (mul( float4( input.position, 1.0f ),
SkinMatrices[input.bone.w] )
* input.weights. w);

// Transform world position with viewprojection matrix
output.position = mul( output.position, ViewProjMatrix );

// Calculate the world space normal vector
output.normal = (mul( input.normal, (float3x3)SkinNormalMatrices[input.
bone.x] )

* input.weights. x) .xyz;
output.normal += (mul( input.normal, (float3x3)SkinNormalMatrices[input.
bone.y] )

* input.weights. y) .xyz;
output.normal += (mul( input.normal, (fioat3x3)SkinNormalMatrices[input,
bone.z] )

* input.weights. z). xyz;
output.normal += (mul( input.normal, (float3x3)SkinNormalMatrices[input.
bone.w] )

* input.weights. w) .xyz;

// Calculate the world space light vector
output.light = LightPositionWS - output.position.xyz;

// Pass the texture coordinates through
output.tex = input.tex;

return output;

}

Listing 8.3. The vertex shader used in the vertex skinning operation.