I'm writing a raytracer and I'm using the assimp library to load objects. I have an object's material specified in a .mtl file:
newmtl rightSphere Ka 0.01 0.01 0.01 Kd 0.01 0.01 0.01 Ks 0.30 0.30 0.30 Tf 0.10 0.10 0.10 Ns 200 Ni 2.5 illum 7
and I'm trying to load this material. I've been mostly successful so far, for example I know that to extract the diffuse component (Kd), I can use
aiMesh *mesh = scene->mMeshes[i]; aiMaterial *mat = scene->mMaterials[mesh->mMaterialIndex]; aiColor3D color; mat->Get(AI_MATKEY_COLOR_DIFFUSE, color);
using the identifiers specified in here. However, I've been unable to extract the Tf component. I understand that this component defines the coefficient of refracted light per color channel, and I need this value along with the index of refraction (Ni) to get it to work.
My question is: how can I get the Tf value?