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renderingraytracingraster

What visual effects can be rendered in ray tracing that are hard or can't be done in current raster engines

As far as I know, the most powerful raster based engines still can't deal with some visual effects. I will list some below and would like to know if I am right or not and what other effects are hard do generate using raster based renderers.

  1. Mirror reflections Cube maps can be used to simulate reflections but if the scene changes a lot, it became a problem to the raster renderer right ?

  2. Curved surfaces Since raster is poligon based ...

  3. Ambient Occlusion Could be easily done for static elements, but what about moving objects ?

  4. Caustics I believe it's possible to simulate but if the object changes in form, the effect can't be easily updates in raster based rendering right ?

  5. Detailed shadows I can imagine leaves moving in a tree...

  6. What else ?

Thanks in advance !

Solution

  • Your #2 is not quite correct (though correct for most hardware rasterizers), and you left out (as #'s 6 and 7?) refraction and various sorts of diffuse scattering (e.g., "final gather" style bouncing).

    All of these effects can be approximated by rasterization, but done in a superior more physics-based way via ray tracing or better yet path tracing.