My vertex shader code is:
struct VertexInputType
{
float4 position : SV_POSITION;
float3 normal : NORMAL;
float2 tex : TEXCOORD0;
};
struct PixelInputType
{
float4 position : SV_POSITION;
float3 normal : NORMAL;
float2 tex : TEXCOORD0;
float3 viewDirection: TEXCOORD1;
};
////////////////////////////////////////////////////////////////////////////////
// Vertex Shader
////////////////////////////////////////////////////////////////////////////////
PixelInputType LightVertexShader(VertexInputType input)
{
PixelInputType output;
// Change the position vector to be 4 units for proper matrix calculations.
input.position.w = 1.0f;
// Calculate the position of the vertex against the world, view, and projection matrices.
output.position = mul(input.position, worldMatrix);
output.position = mul(output.position, viewMatrix);
output.position = mul(output.position, projectionMatrix);
output.position.z = log(zNear*output.position.z + 1) / log(zNear*zFar + 1) * output.position.w;
// Store the texture coordinates for the pixel shader.
output.tex = input.tex;
// Calculate the normal vector against the world matrix only.
output.normal = mul(input.normal, (float3x3)worldMatrix);
// Normalize the normal vector.
output.normal = normalize(output.normal);
float4 posWorld = mul(input.position, worldMatrix);
output.viewDirection = float4(cameraPosition,0) - posWorld;
return output;
}
