Direct lighting from tens of thousands of lights with real-time frame rates directly inside the viewport.
|hdRstr for Houdini 18.5 (90-day trial)||$0||1 seat, floating, 90-day trial|
|hdRstr for Houdini 18.5||$50||1 seat, floating perpetual (special introductory price)|
|hdRstr for Maya 2022 (90-day trial)||$0||1 seat, floating, 90-day trial|
|hdRstr for Maya 2022||$50||1 seat, floating perpetual (special introductory price)|
|hdRstr_v107beta_hou185.zip||v1.0.7-beta for Houdini 18.5|
|hdRstr_v107beta_hou185_py3.zip||v1.0.7-beta for Houdini 18.5 (for houdini-py3-18.5.*)|
|hdRstr_v107beta_maya2022_usd012.zip||v1.0.7-beta for Maya 2022 with maya-usd 0.12.0|
|hdRstr_minidemo1.hipnc||Minimal demo scene for Houdini|
|hdRstr_minidemo1.mb||Minimal demo scene for Maya|
The primary intent is a very fast viewport renderer, that is able to show a good approximation of the final direct (and more limited indirect) lighting in real-time. It is designed to be used alongside other viewport renderers.
Maya: No. Hydra render delegates can be used as VP2 replacement. Only the official maya-usd plugin is needed. There may be limitations for some materials and lights.
Houdini: Sort of. Hydra render delegates are only active in the Solaris view (/stage). It can not be used to directly render non-LOP nodes.
Maybe. If the quality is good enough for a production it could certainly be used as a final renderer. People are using game engines for production rendering now, and they seem to be happy with the very limited lighting capabilities. Expect game engine quality with much, much better lighting.
Call it scientific and/or technical progress. Without real-time ray tracing there was no real need for very fast light sampling. Then the inventors of ReSTIR looked at Monte Carlo methods previously not used in path tracing and found a way to improve it vastly (at the expense of some precision). And the RTXDI and NRD developers made it production-ready.
No. It should run on any hardware supporting DXR 1.1 (or the Vulkan Ray Tracing Extensions, see below). Practically there are currently not much devices from other vendors available or in use, so this is not really tested.
This is planned. A Vulkan-based version is technically possible and doable.
Tricky. One would need to use Vulkan with MoltenVK, which does not seem to support ray tracing. But in theory it could go like this: Most shaders are just compute shaders working on buffers. This part should work with MoltenVK. The ray tracing part just fills a G-Buffer. This could be separately done with Metal (indirect lighting currently traces rays "on the fly" from a compute shader, but this could be redesigned). So, if there is enough demand (and ray tracing hardware), it may be worth a try. But at the moment there a no plans.
1. Benedikt Bitterli, Chris Wyman, Matt Pharr, Peter Shirley, Aaron Lefohn, Wojciech Jarosz. Spatiotemporal reservoir resampling for real-time ray tracing with dynamic direct lighting. ACM Transactions on Graphics (Proceedings of SIGGRAPH), 39(4), July 2020. DOI:https://dl.acm.org/doi/10.1145/3386569.3392481. Link to author's version.