Nvidia’s “Zorah” tech demo has been updated to showcase more RTX technologies with the RTX 5090.
At the end of January, shortly before the release of the RTX 5090 and RTX 5080, Nvidia presented a new tech demo called “Zorah” that is supposed to show the “future of rendering”.
- According to the company, half a billion triangles per scene and 30,000 different materials were processed within the Zorah sequence.
- 2,000 particle lights and 1,500 textures provided atmospheric lighting.
Thanks to DLSS 4 with Multi Frame Generation, a smooth frame rate was still possible – even though, as with any upscaling, the question of increased latency remains, which Nvidia has not answered.
Undeterred, the developers continue to work on the Zorah tech demo, which has recently received a new update and is supposed to max out the potential of the RTX 5090. You can find the new sequence in the YouTube video embedded below:
- As in the original version, the tech demo focuses on detailed environments with complex geometry and sophisticated lighting, which are displayed in real time on a Geforce RTX 5090.
- In addition, Nvidia also mentions “ReSTIR Pathtracing” and “ReSTIR Direct Illumination”, which are responsible for the lighting calculation; as well as “RTX Mega Geometry”, which was previously only used in Alan Wake 2.
If you only understand train station when you see these terms, we have packed a short (and very simplified) glossary of the respective Nvidia technologies for you here:
Neural Rendering
Neural rendering uses artificial neural networks for certain aspects of graphics representation. In contrast to conventional rendering methods, this approach can make computationally intensive processes more efficient.
A central element are the RTX Neural Shaders from Nvidia. These enable the training and use of small neural networks within shader programs that are responsible for textures, materials, lighting and volumetric effects. According to Nvidia, this should lead to improvements in performance, image quality and interactivity.
ReSTIR Pathtracing
ReSTIR Pathtracing (or “ReSTIR GI”) is a path-tracing algorithm for indirect lighting that was developed specifically for parallel GPU architectures. This technology is responsible for the part of the lighting that affects the indirect light – light that is reflected from other surfaces.
The algorithm builds on the screen-space spatio-temporal resampling principles of ReSTIR and allows for the resampling of indirect lighting paths obtained through path tracing. This allows information about important paths that contribute to illumination to be shared over time as well as across different pixels in the image.
ReSTIR Direct Illumination
RTX Direct Illumination (RTXDI) is the part of raytracing illumination that deals with direct light. This technology was developed to increase the number of complex direct light sources in games, which has often been very limited so far.
RTXDI combines ray tracing with a high-performance version of the ReSTIR algorithm and ReGIR (Reservoir-based Grid Importance Resampling). While ReSTIR is used for primary surfaces, ReGIR takes care of secondary surfaces.
The algorithm deals with so-called “hero lights” – while in games only a few selected light sources were previously responsible for casting shadows, with this technology it should no longer matter whether dozens, hundreds or millions of light sources are needed.
RTX Mega Geometry
RTX Mega Geometry technology accelerates the raytracing of complex geometries and, according to Nvidia, enables a significantly higher number of triangles than before.
Apart from that, Nvidia explains in the course of the Zorah tech demo that RTX Mega Geometry will be available to developers in the future via the NvRTX branch of Unreal Engine 5. This should make it easier for upcoming games to integrate the technology.
