Specular reflection is a type of reflection off of smooth surfaces such as mirrors. Another kind of reflection is called diffuse reflection which is off of rough surfaces such as cloth or asphalt. Instead of reflecting light uniformly like on a smooth surface, a rough surface will reflect light in many different directions although they may hit the same area. More on specular and diffuse reflection here: https://www.physicsclassroom.com/class/refln/Lesson-1/Specular-vs-Diffuse-Reflection
Carpetfizz
@tigreezy does that suggest that rendering a scene with objects with diffuse material is more expensive than rendering a scene with specular material? It seems like we would have to simulate the propagation of several more rays in order to achieve the "scattering" effect.
Staffirisli
@Carpetfizz: The expensiveness of something is just how much you want to pay. With a diffuse material, you could just decide to sample a few random sub rays. The wider your recursion, the less noisy the result will be.
But if you want to get to a quality of something without artifacts at all, it would be more expensive. Thats why Pixar films take more than 24 hours to render a single film.
Specular reflection is a type of reflection off of smooth surfaces such as mirrors. Another kind of reflection is called diffuse reflection which is off of rough surfaces such as cloth or asphalt. Instead of reflecting light uniformly like on a smooth surface, a rough surface will reflect light in many different directions although they may hit the same area. More on specular and diffuse reflection here: https://www.physicsclassroom.com/class/refln/Lesson-1/Specular-vs-Diffuse-Reflection
@tigreezy does that suggest that rendering a scene with objects with diffuse material is more expensive than rendering a scene with specular material? It seems like we would have to simulate the propagation of several more rays in order to achieve the "scattering" effect.
@Carpetfizz: The expensiveness of something is just how much you want to pay. With a diffuse material, you could just decide to sample a few random sub rays. The wider your recursion, the less noisy the result will be.
But if you want to get to a quality of something without artifacts at all, it would be more expensive. Thats why Pixar films take more than 24 hours to render a single film.