Hi all!

Considering that many 3D applications (eg games) use single precision for their
renders, I am wondering where we really need double precision for 'normally'
sized scenes. I mean scenes that do not mix microscopic and gigantic distances.

For sure, if the dynamic is huge, we absolutely need double precision, at least
for object coordinates. But, if the dynamic in distances is reasonable, is it
mandatory to use double precision for the following features :

    ray - bounding box intersection tests ?
    ray - object intersection computation ?
    others (TBD) ?


Independantly from the dynamic in scenes and from CPU hardware considerations
(see
http://research.colfaxinternational.com/file.axd?file=2012%2F4%2FColfax_FLOPS.pdf),
why would single precision not be sufficient for :

    RGBFT values storage, which might imply :
        radiosity/photon maps elaboration ?
        texturing and lighting ?
    media (even though it uses integration methods)
    others (TBD)

What do you think ? Has the subject already been debated here ?


    Bruno.

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