Hello everyone, I’ve been fighting with this problem for a few days now and cant seem to figure out the issue.
I am working with a high-poly detailed model of a vehicle with over 45mio polygons. I have imported the model using the datasmith format (exported from blender using the datasmith exporter add-on) via a dataprep asset.
In the Dataprep asset itself I am simply applying a Material Substitution table to assign all of my UE materials and then merging the objects.
I am doing this separately for the wheels, interior, exterior, glass objects, the centre console flap (so I can animate it) and the seats. This means I end up with 6 objects.
Due to the High polygon count I need to enable nanite so that my fps jumps from 25/30 to around 70/80.
Unfortunately when enabling nanite I encounter a few problems:
First Problem - Low Poly Results
For some reason, my models seem to get optimized when enabling nanite and result in chunky, low-poly looking meshes, even from up close where 100% of the triangle count should be used.
In this image you can see the ambient light ring, the circular air vents and the Centre Console flap being very low poly. The reflections on the black bar (top left) are also very bad.
I’ve tried various settings:
- Reducing the “Fallback Target Relativ Error” to 0
- checked the object scale (its imported correctly)
- checked screen percentage (yes its set to 100%)
- decreased “r.Nanite.MaxPixelsPerEdge” to 0.2 and still no change
As you can see here, the normals themselves are fine on the nanite version
and here the non-nanite version:
I find it odd that the triangles on e.g. the centre console flap are optimized very much compared to the centre consoel around it. One could argue that the object is flat and therefore can be optimized more, but as you can see from the image above, the corners are completely broken.
What am I missing here?
Second Problem: Shading Issues
I need raytrace shadows enabled. When enabling nanite my geometry receives very weird shading issues as can be seen below:
Yes I have tried applying all fixes noted in william fauchers video.
The only thing that remotely worked was reducing the “Fallback Target Relativ Error” to 0, however, even then I had some artefacts which are not acceptable in my scene.
To fix the issue, I currently have “r.RayTracing.NormalBias” set to 3, however this brings its own shading problems with it, so I’d like to see if there are alternatives you guys might be able to suggest.
I would very much appreciate any help I can get on this matter as I cant find anything about this online.