guys. let me give a suggestion for a better subdivision. as we know now we have adaptive subdivision to use displacement more efectively. but i was thinking about another method which may be even more effective. i suggest to make an option for subdivision modifier to use a displacement texture. the texture will tell where the mesh needs to be more subdivided. the displacement texture is always blured. almost. and has sharp pixels only in that areas where the mesh need to go higher or lower. it may be great if the subdivision density will deppend on the texture. so we will have subdivisions only there we really need. the more sharper are pixels on displacement map the more dense will be subdivision in those areas. and less dense where it is not really needed. also optionally let it have density threshold to adjust it manually. and even also let it use dicing camera as usually does.
an example. here we have a simple plane with an adaptive subd modifier. here i use a tiles displacement texture which is very clean. but the subdivisions are visible even there on flat areas of tiles. we dont need there to have subdivisions. but only on corners and edges of tiles.