NVRTX 5.1 caustics review (ish)

[daadaa (DeltaA)]

Hey Johnny and hope you’ve had a great xmas!

1 - Caustics bleed
In the screenshots I have a dark object with a chrome edge casting caustics onto the floor below. When can camera turns to the otherside, this caustics will bleed onto near by objects. In UE4 it seems distance dependent while in UE5 it seems angle dependent… not sure why theres a difference.

2 - DOF in reflections at shallow angles but like I said before this is to be expected for agame engine. (review earlier was in perspective of archviz use so in comparasion to engines like vray)

3 - However I noticed a new bug while trying to create these screenshots. CineCamera seems to be incompatitble with Light Tracer? I wanted to do a comparason but crashes every time. This is only for UE5 and works fine for UE4.

4 - IncludeDOF - most obivous in CineCam + DOF + DLSS
Just to note this artifact is on all materials except translucent when incDOF is switched on, and happens on both UE4 and UE5 (bauball below is chrome)

5 - Anisotropy works fine in UE5 but breaks materials for nanite meshes… documented before:

Mixture of Nanite and Non-Nanite meshes breaks lighting

I upgraded a project I had from UE 4.26 to UE 5 and then converted my meshes to Nanite, but there were certain models that didn’t work with Nanite so I didn’t convert them. But I instantly noticed something wasn’t right with the lightning in the scene anymore. After some testing and troubleshooting I found that the issue is that if you have both Nanite enabled meshes and non-Nanite enabled meshes it causes the light to not render on objects properly. I created an empty scene with 3 objects as a…

• anisotropic effect in headphones (and all the screenshots above) are rendered in UE472

Currently I have both UE4 & 5 installed. UE4 is still my default engine due to better intergration of all aspects of lighting + effects under raytracing with UE5 being used for specific tasks.

UE5 lumen is great for general but fails when HD reflections are needed, Raytrace is great for perfect reflections but does not EvalSkylight. So overall its usable but UE472 Caustics is just better rendering wise.

UE5 also crashes ALOT (even with simple scenes), esp with sequencer… I havent used non caustics UE5 (or 4 for that matter) so not sure if its related.

Thanks for reading, hope the feedback is useful!