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c++raytracingpbrembree

Should I use Intel Embree via API or via the project's source code itself?

I am thinking about using Intel Embree in my renderer and currently playing around with Embree tutorials.

So, the question is, is it possible to use Intel Embree efficiently via API?

I mean, I can see that the functions from <embree2/rtcore.h>, <embree2/rtcore_ray.h>, e.t.c use some internal data structures like RTCRay. And obviously, since I can't overload any operators I always have to cast my data structures to Embree data structures and vice versa. And that's not even just a type cast, that's a construction of a new object.

For example, before calling rtcIntersect(RTCScene scene, RTCRay ray); I construct RTCRay ray from my Ray class object and then when the function returns some data, I copy some values back.

It doesn't look like a good way to use Intel Embree.

Solution

  • Constructing RTCRay, use rtcIntersect, then copy the data back. The overhead is negligible (<0.5%) compared to ray-traversing and primitive intersection.

    I think Corona render uses RTCRay internally, so they save the 0.5% overhead.

    I know that V-Ray does exactly constructing RTCRay, use rtcIntersect, then copy the data back.

    General advice: Avoid premature optimization. Implement working code and then use profiler to guide your optimizations.