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Optix 6.0 Path Tracing demo

Posted: Fri Feb 08, 2019 3:11 pm
by jbikker
Hi all,

Since the release of Optix 6.0 a few weeks ago I have been playing a bit with the new RTX support. Here's a demo that should run on Maxwell, Pascal and Turing, which allows a direct comparison of the ray tracing performance of these platforms. Spoiler: Turing fares well.

http://www.cs.uu.nl/docs/vakken/magr/20 ... _v0.1a.zip
http://www.cs.uu.nl/docs/vakken/magr/20 ... _v0.2a.zip
http://www.cs.uu.nl/docs/vakken/magr/20 ... _v0.3a.zip
http://www.cs.uu.nl/docs/vakken/magr/20 ... o_v0.4.zip
http://www.cs.uu.nl/docs/vakken/magr/20 ... _v0.4b.zip (March 1)

New in version 0.4b:

- Greatly improved contact shadows when filtering.
- No (well, far less) color bleeding on nearby surfaces when filtering.
- HUD with FPS counter and instructions (can be toggled).
- Removed AVX2 dependency; should now work on more systems.
- Splash screen. :)

This is an 'under construction' demo which may or may not crash on your machine and so on. More updates will follow.

NOTE: this demo requires *very* recent drivers.

- Jacco.

https://youtu.be/uEDTtu2ky3o
https://youtu.be/BDvkoSDTUxc (older video)
sponza2a.jpg
sponza2a.jpg (126.35 KiB) Viewed 2603 times

Re: Optix 6.0 Path Tracing demo

Posted: Fri Feb 08, 2019 4:41 pm
by Tristan
Thanks for sharing.

Re: Optix 6.0 Path Tracing demo

Posted: Mon Feb 18, 2019 7:38 pm
by jbikker
Updated first post with new demo.

Re: Optix 6.0 Path Tracing demo

Posted: Tue Feb 19, 2019 3:24 am
by olliej
Would you mind if I used your version of the sponza model to test my own renderer?

The various open licensed versions I've found lack the detailing and have some questionable texture coords.

Also it's nice to be able to be able to compare exact scene rendering to an actual good renderer :)

Re: Optix 6.0 Path Tracing demo

Posted: Tue Feb 19, 2019 7:32 am
by jbikker
Please go ahead. But I think this is straight from McGuire's page?

Re: Optix 6.0 Path Tracing demo

Posted: Wed Feb 20, 2019 2:27 am
by olliej
It is indeed -- I wonder if I dismissed it due to my RT not being able to handle it earlier.

Now to work out why my photon mapping is weird and blown out.

Re: Optix 6.0 Path Tracing demo

Posted: Wed Feb 20, 2019 6:58 am
by olliej
@jbikker: ok, possibly dumb question - how do you handle convert the emission coefficients from the wavefront into optix? I'm doing the dumbest thing possible with and doing ke * light colour ?

Re: Optix 6.0 Path Tracing demo

Posted: Wed Feb 20, 2019 8:02 am
by jbikker
Well I think this deserves its own topic. :) I don't handle this at all; the demo uses unidirectional path tracing only, no photon mapping.
But what I got for photon mapping is: lightcolor * dot( D, N ) / lightPdf, where D is a cosine-weighted random direction with pdf = (dot( D, N ) / PI) / lightArea and N is the normal at the light source. Note that the dot(D,N) cancels out in this case, but I prefer to leave it in to make the application of the pdf clear.

Re: Optix 6.0 Path Tracing demo

Posted: Thu Feb 21, 2019 1:13 am
by olliej
Okie dokie :)

I'm still trying to work out what it should be doing (this is my first real attempt to implement PM). I'm getting a huge blow out on the direct photons, and a rapid drop in the propagation following the first bounce. (I'd search the board but photon mapping is apparently too common to use as a search term :( )