3 ms·

For context, PBRT (a popular open-source CPU renderer) took a crack at it: Total rendering time using a 12 core / 24 thread Google Compute Engine instance runn

For context, PBRT (a popular open-source CPU renderer) took a crack at it: Total rendering time using a 12 core / 24 thread Google Compute Engine instance running at 2 GHz with the latest version of pbrt-v3 was 1h 44m 45s.

dahart 6y ago
Yeah but how long does PBRT take if limited to 8GB ram? ;)
- packetslave 6y ago
  I mean... "When rendering the latest Moana island scene, pbrt-v3 uses 81 GB of RAM to store the scene description. Today’s pbrt-next uses 41 GB"
  - dahart 6y ago
    Oh that’s cool, I didn’t realize pbrt-next was that much leaner. Yeah I was asking a nonsense question, but just tongue-in-cheek trying to hint that we shouldn’t compare PBRT run times to Chris’ project to render Moana on a 2070, they’re solving different problems. Chris’ renderer is also brand new and hasn’t had a chance to evolve the way PBRT did. But all that said, it’s very impressive IMO to render the whole scene with (cpu)Ptex using such a small GPU without it taking far longer. I happen to know for a fact that it’s possible to render Moana much faster than cpu-pbrt if you have access to one of the 48 GB models and don’t need to use out-of-core techniques.
  - chellmuth 6y ago
    I tried to run the pbrt scene locally for timing comparisons, and it kept running out of memory. Thanks for that quote- I realize now that I forgot to switch to the pbrt-next branch. In general, this project has a ton of room left for optimization, so I hope to catch up and maybe pass pbrt. But I'd imagine that a commercial cpu renderer would also perform much better than pbrt.
    - moyix 6y ago
      I'm not clear on where the pbrt-next branch is, but an early release of PBRTv4 is here: https://github.com/mmp/pbrt-v4 https://github.com/mmp/pbrt-v4
    - packetslave 6y ago
      yeah, PBRT is in an interesting place when it comes to changes and optimization. They have an explicit goal of keeping the current released repository as close to the book ("Physically-Based Rendering") as possible, so all of the optimizations and changes go into -next. Matt's blog talks a _lot_ about all the optimizations he had to do just to get the scene to _load_ in PBRT. It's a beast.

dahart 6y ago

Yeah but how long does PBRT take if limited to 8GB ram? ;)

packetslave 6y ago
I mean... "When rendering the latest Moana island scene, pbrt-v3 uses 81 GB of RAM to store the scene description. Today’s pbrt-next uses 41 GB"
- dahart 6y ago
  Oh that’s cool, I didn’t realize pbrt-next was that much leaner. Yeah I was asking a nonsense question, but just tongue-in-cheek trying to hint that we shouldn’t compare PBRT run times to Chris’ project to render Moana on a 2070, they’re solving different problems. Chris’ renderer is also brand new and hasn’t had a chance to evolve the way PBRT did. But all that said, it’s very impressive IMO to render the whole scene with (cpu)Ptex using such a small GPU without it taking far longer. I happen to know for a fact that it’s possible to render Moana much faster than cpu-pbrt if you have access to one of the 48 GB models and don’t need to use out-of-core techniques.
- chellmuth 6y ago
  I tried to run the pbrt scene locally for timing comparisons, and it kept running out of memory. Thanks for that quote- I realize now that I forgot to switch to the pbrt-next branch. In general, this project has a ton of room left for optimization, so I hope to catch up and maybe pass pbrt. But I'd imagine that a commercial cpu renderer would also perform much better than pbrt.
  - moyix 6y ago
    I'm not clear on where the pbrt-next branch is, but an early release of PBRTv4 is here: https://github.com/mmp/pbrt-v4 https://github.com/mmp/pbrt-v4
  - packetslave 6y ago
    yeah, PBRT is in an interesting place when it comes to changes and optimization. They have an explicit goal of keeping the current released repository as close to the book ("Physically-Based Rendering") as possible, so all of the optimizations and changes go into -next. Matt's blog talks a _lot_ about all the optimizations he had to do just to get the scene to _load_ in PBRT. It's a beast.