twod

twod

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OpenCL Performance on different GPU's Aug. 17, 2018, 8:33 a.m.

How big were the pyro volumes? In order to fully take advantage of massive parallism, the job needs to be diced into pieces to feed all the compute units. If the volume isn't large enough, some of those units will be starved, amd the overall speedup lessened. There is also some cpu overhead for the non-CL work which will become a greater portion of the total cook time as the CL time decreases. Eventually it'll settle to around the speed of the non-CL time as the CL compute becomes near-instant.

IOR vs Reflectivity ? Transparency vs Opacity? Aug. 16, 2018, 11:52 a.m.

IOR values less than 1 are physically impossible. It would mean that the speed of light within the medium is faster than the speed of light in a vacuum (C). So far we haven't found any medium that accelerates light to faster than C.

IOR vs Reflectivity ? Transparency vs Opacity? Aug. 16, 2018, 10:02 a.m.

Index of Refraction is an actual physical material property that you can look up for a real material. Air is almost 1, Water is 1.33 and glass is 1.5. It wouldn't be very helpful to remap it to some other range.
https://en.m.wikipedia.org/wiki/List_of_refractive_indices [en.m.wikipedia.org]