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From: Lawrence D'Oliveiro <ldo@nz.invalid>
Newsgroups: comp.arch
Subject: Re: Misc: Applications of small floating point formats.
Date: Sat, 3 Aug 2024 00:07:15 -0000 (UTC)
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On Fri, 2 Aug 2024 03:56:35 -0500, BGB wrote:

> For batch rendering, it doesn't really need to be efficient though.

Of course it does. Ray-traced renderers can compute hundreds or thousands 
of rays per pixel, taking anywhere from minutes to hours per frame. This 
is how you produce those cinema-quality 4K (or even 8K) frames. Anything 
that can shave a little bit off the time for a single ray computation can 
very quickly add up.

> General strategy would be to setup a context, render to the context, and
> then fetch the rendered image using glReadPixels or similar.
> 
> The "glReadPixels()" function is not exactly new...

Almost verging on useless, in my (albeit limited) tests. OpenGL, Vulkan 
and the like are targeted towards on-screen rendering, and that’s what you 
should stick to using them for.

Don’t confuse this with the fact that programmable GPUs are adaptable to 
run SIMD-oriented compute APIs like OpenCL/SYCL (and their proprietary 
rivals), and that these are commonly used to implement high-quality 
offline renderers like those I mentioned above. These have nothing to do 
with OpenGL.