You can use selected > triangulate mesh and hope the light reflects better, or you can set the shader to 'constant' in the material properties (where the texture is) to negate shadow and thus negate any light affecting poorly created meshes.
As a last resort select an object, and go to object > mesh smoothing for a subdivision.
Finally, try moving the lighting position by clicking on the globe in the lighting panel on the left. You can get away with it sometimes if you shine light at the right angle 
As a last resort select an object, and go to object > mesh smoothing for a subdivision.
Finally, try moving the lighting position by clicking on the globe in the lighting panel on the left. You can get away with it sometimes if you shine light at the right angle