Matching GLSL Normals to VrayNormals

[im.thatoneguy]

I'm attempting to just establish a baseline vrayGLSL Normal map shader which maintains the geometric normals. However I'm having trouble using the vr_CameraToWorld to transform cameraspace normals into worldspace normals.

vec3 wNormal()
{
   vec3 cNormal = vr_Normal;
   vec4 worldvec = vr_CameraToWorld * vec4(cNormal.x,cNormal.y,cNormal.z,0.0);
   return vec3(worldvec.x,worldvec.y,worldvec.z);
}

I'm sure it's something incredibly obvious but I'm not sure what the correct matrix operation is to transform screen tow orld.

[im.thatoneguy]

Ok... it was in fact mighty stupid. Correct function puts the transformation matrix on the right hand side. Although in my defense I was following the instructions in the documentation which state:

http://docs.chaosgroup.com/display/V...port+in+V-Ray#

NOTE: When using the transformation matrices, always place the vector to be transformed on the right-hand side.

vec3 wNormal()
{
   return (vec4(vr_Normal, 0.0) * vr_CameraToWorld).xyz;
}

Just a note on a weird quirk. Y is inverted in Max's shading space?