A comparison with and without normal maps

I implemented a normal map into my tiny graphics engine (I’ve gotten by mostly with phong shading for my research work, so yeah I should do more graphics stuff I thought), and also to learn about tangent space. I saw firsthand the remarkable difference a normal map brings.

Map without normal map

without-normal-map

Map with normal map (same lighting as above)

with-normal-map

It’s pretty cool how much more detail a normal map brings into your models. Hope to integrate more features like this.

Loading Shininess in Materials when using Assimp

I was looking around on how to get the shininess (aka the specular coefficient, specular exponent) from a loaded model, when using the Assimp APIs (4.1.0). Unfortunately, nothing in the docs helped me and I had to look into some sample programs to get the answer. So, here’s how to do it:

// material index is the ID of the material you are interested in
	const aiMaterial* ai_material = scene.mMaterials[material_index];
float shininess;
if(AI_SUCCESS != aiGetMaterialFloat(ai_material, AI_MATKEY_SHININESS, &shininess))
    {
// if unsuccessful set a default
shininess = 20.f;
    }

Here’s an example to get some other property like specular color using Assimp’s structs.

aiColor4D spec_color;
 if(AI_SUCCESS != aiGetMaterialColor(ai_material, AI_MATKEY_COLOR_SPECULAR,
        &spec_color))
    {
        spec_color = aiColor4D(1.f, 1.f, 1.f, 1.f);
    }

HTH