//we need to recalculate the normals too, because we need just one normal,tangent, bitangent per vertex
//In the case of a textureless object, we don't need tangents for our shader and so we skip this step
//TODO: Use a better function to calculate tangents
//we need to recalculate the normals too, because we need just one normal,tangent, bitangent per vertex
//In the case of a textureless object, we don't need tangents for our shader and so we skip this step
//TODO: Use a better function to calculate tangents