Following up on my earlier post about visualising damp and decay. We have made some progress on the material side and wanted to share what worked and ask a couple more questions.
For simulating moisture staining on masonry we ended up using a layered material with a height blend between dry and wet states, driven by a vertex painted mask. The results look convincing enough for client presentations. For mould growth we used a simple noise pattern overlaid on the wet areas which gives a decent effect without too much performance cost.
The timber side is still the weak point. We are trying to recreate what happens when dry rot attacks structural beams, where the wood develops a distinctive cuboidal cracking pattern and becomes brittle and crumbly. We work in the property care sector and deal with this kind of damage regularly so we have plenty of reference photography from our own survey work at damp proof course installations and timber inspections.
The cuboidal fracture pattern is the tricky part. We have tried displacement maps generated from our survey photos but the results look flat compared to the real thing. Has anyone had success with parallax occlusion mapping for this kind of deep surface detail, or is tessellation still the better option in UE5 for close up architectural walkthroughs?
Also interested in whether anyone has used Nanite for this type of scanned geometry. We are considering photogrammetry of actual damaged timber samples but not sure if the polygon count would be manageable even with Nanite.