Single mesh could not hold that much poly in LuxRender, it had to be divided in parts.
Around 95 Gb for render.
Leather uses loop subdivide displacement procedural map.
Metal parts microdisplacement, here the smooth shading had to be turned off because shading issues with microdisplacement.
Both use roughness maps.
95 gigabytes!? I thought Luxrender Microdisplacement used an on-the-fly trace and forget technique (slow, but allows for a tiny memory footprint). Unless something changed that is (or the LuxCore part of the engine simply doesn’t use it).
So it seems this is impressive as a test, but I would still argue for the use of general bumpmaps if the displacement is small enough to not cause a notable impact on edges.
Something weird with microdisplacement and smooth shading when displacement scale is higher.
Compared to loop subdivscheme displacement, the micro seems to suffer some shading issues where everything is black or you can see through mesh, and its dead slow.
The skin part has scale 0.0006 m, the micro was not possible. The speed drop was from 1M S/s to 100-1000 S/s.
With scale of 0.0000035 on camera body, the micro gives me 100k-500k S/s, but i have to render with solid shading and the triangles were visible on initial render, so i upped the subsurf by 4 levels.
The scene has 593 112 530 Triangles + microdisplacement 6 div.
It also comes to mind that whatever Luxrender uses for fast micro-displacement rendering, it’s doesn’t seem to even be close to being as efficient as it can be (if this represents the most optimal way).
95 GB for a single camera model, you can do the same thing in Cycles (getting similar results) using a tenth or less of the memory (after you shrink the polygon size to below three-quarters of a pixel, you don’t get a lot of visual difference in most cases). Mai even has a falloff patch in the tracker which can create a dramatic cut off of that even.