What is wrong with my specular phong shading
- by Thijser
I'm sorry if this should be placed on stackoverflow instead however seeing as this is graphics related I was hoping you guys could help me:
I'm attempting to write a phong shader and currently working on the specular. I came acros the following formula: base*pow(dot(V,R),shininess) and attempted to implement it (V is the posion of the viewer and R the reflective vector). This gave the following result and code:
Vec3Df phongSpecular(const Vec3Df & vertexPos, Vec3Df & normal, const Vec3Df & lightPos, const Vec3Df & cameraPos, unsigned int index)
{
Vec3Df relativeLightPos=(lightPos-vertexPos);
relativeLightPos.normalize();
Vec3Df relativeCameraPos= (cameraPos-vertexPos);
relativeCameraPos.normalize();
int DotOfNormalAndLight = Vec3Df::dotProduct(normal,relativeLightPos);
Vec3Df reflective =(relativeLightPos-(2*DotOfNormalAndLight*normal))*-1;
reflective.normalize();
float phongyness= Vec3Df::dotProduct(reflective,relativeCameraPos);
if (phongyness<0){
phongyness=0;
}
float shininess= Shininess[index];
float speculair = powf(phongyness,shininess);
return Ks[index]*speculair;
}
I'm looking for something more like this:
