Hi @Greg_Ward many thanks for the references and the short of explanation, appreciated. I’ve also found another old thread where you are also explaining a short of pipeline to be used. I will try to create a kind of Wavefront2Radiance translator and possibly share it here. Just to clarify for the color is it the values from Kd or Ka that I should be using because above you mention Kd but in your older message you say Ka and Terrance also refers to Ka to be used for color.