Raytracing FAQs
How do I render a still frame with raytracing and antialiasing, without enabling them in the viewport?
Raytracing can be enabled manually or by using the Python command: toggleRaytracing(true).
The stillframe antialiasing setting does not matter, as it is taken from Render Settings when rendering to file. The render settings have their own setting for this, the Supersampling option in the File Output tab.
GPU vs. CPU Raytracing
Video captions: Open the Render Settings, via the Quick Access Bar. Select under Raytracing Quality, CPU Raytracing for both Interactive and Still Frame. Activate the Raytracing mode. The CPU rasterization mode is in principle, identical to the OpenGL mode, just that the computational processes are handled by the CPU. Using this mode is reasonable, should the performance of your graphics card not be sufficient or if large sets of data are used.
When raytracing, we compared a Dual CPU Workstation with 40Cores/80Threads in total with 1, 2, and 3 RTX 8000 GPUs. Here are the results:
- 1 RTX 8000 GPU was about 2.3 times faster than the Workstation.
- 3 RTX 8000 GPUs were about 6.6 times faster than the CPU Raytracer.
However, there are some things to keep in mind:
The comparisons were made with the same scene settings.
Not all features are yet supported on the GPU, and some probably never will be, such as some of the pixelfilter or quality overrides. So, when using photonmapping, you might get better performance with CPU raytracing.
A GPU with lots of memory is needed to work with standard automotive datasets. For professional work, at a minimum, we recommend, a Quadro RTX 5000, Titan RTX (not officially supported), or Quadro RTX 6000. For large scenes, use a Quadro RTX 8000.
Memory sharing, via NVlink, is not yet supported; however, we are planning to add it. When this happens, it is important to know this will have a cost to performance.
How do You Choose the Best Resolution Without Impacting Performance?
Resolution minimally impacts performance when raytracing, since mipmapping chooses the appropiate level for each pixel. So, when making a decision regarding resolution, look at the amount of free memory, as it is impacted more by higher resolutions.
Can I GPU Raytrace Using Remote Desktop?
Yes. If you have to remotely access your rendering workstation, you will need Quadro GPUs.
NVIDIA provides Windows Remote Desktop support for NVIDIA GeForce GPUs, a feature that has previously only been available on enterprise Quadro boards.
Log on as an NVIDIA Developer to get access. After this, a link will enable you to access the software you’ll need: https://developer.nvidia.com/designworks.
As of version 2022.1, you must use GeForce drivers 456.71 or later for Windows or 455.28 for Linux.
For the latest driver requirements, check the VRED system requirements.
Once you download, launch the executable as administrator on the machine running the OpenGL application to enable OpenGL acceleration. A dialog will be displayed to show whether OpenGL was enabled and if rebooting is required.
How to Render a Transparent Background Using Raytracing?
Turn the visibility of the environment off. Since, it is geometry, like any other kind of geometry in raytracing, it is not transparent. To do this, go to the environment material and toggle off the visibility.