Naturally looking cracks in SD?
polycounter
Does anybody knows any fresh approach to do nice naturally looking cracks ? What I saw so far was mostly variations of Cells noises. Imo they are not doing any real looking cracks and instantly recognizable as artificial.
I understand that a true crack generation could be a super complicated task involving physics calculation , tension zones etc. But perhaps some fresh idea of how to make those cells less similar to each other could do the trick.
I understand that a true crack generation could be a super complicated task involving physics calculation , tension zones etc. But perhaps some fresh idea of how to make those cells less similar to each other could do the trick.
Replies
Anyway, using cells is, okey-ish, I like to use them for narrow cracks, for larger ones I like to use the old distance node + edge detect trick.
In all cases I always blend multiple crack versions, i.e. if I use cells I will use levels to create some cracks that are very thin, some that are thick, some that have a slight bevel etc, and then blend those together using a blend node set to copy, with a noise plugged in as mask.
Blending a noise over your cracks using a minimal screen blend can also help a lot, as it breaks up the constant depth a bit.
For me key in making cracks feel natural is using a slight directional warp with whatever surface they are digging into as input, i.e. bricks, this will at least "ground" them more in the texture. This doesn't quite apply for very flat surfaces.
After that I also like to warp them using a noise, I quite like the result of clouds 2, if you warp it with say, 20 intensity, that breaks up the obvious lines and suggest more natural caused damage. The intensity of this one will of course depend on the material and damage.
After that a slope blur can do wonders, cloud noises can help you created layer effects in those, BnW spots more roughed up edges, perlin zoom hard chips, just experiment with different setups.
If you use slope blur I'd also recommend you blend the blurred version over a clean one with a noise as mask, otherwise it gets way too uniform.
I'd paste some sample setup pictures in here but I don't have access to my workstation at the moment, sorry.
Hope some of these ideas will help!
I did tried to use distance node with sampler input but it always make pretty much same cells with same recognizable corners, not much different from Cell itself. So I still have no idea how to do something having certain dominant crack direction, crack branching etc
For example something like this
Notice how the asphalt "cells " have some pretty specific order around initial straight crack, not just totally random and more or less squarish,rectangular shape .
In a word I don't see Distance node making any more structured cells .
Years ago I managed to do nice cracks with Algorithmic "Map zone " since it allowed to manually recompose noise clusters but now it's not that easy.
Somethimes , very rarely it turns right in SD suddenly but it's non stop dice throwing . Next variants are never real.
And another problem is how to do subtle slant(depth gradient) withing those asphalt "cells"
Crack branching would very hard to achieve on some surfaces, in the one you show above you could create the initial crack and place two cell generate cracks on either side, like two loose plates, but that is of course far from ideal, let alone a solution.
For the rectangular shapes you can of course scale them in a transform or warp them upwards, you'll quite rapidly achieve that effect.
For the slant I assume you mean that some of those plates are slightly skewed? In that case you could actually try and somehow make the distance node work for yourself, you could use a tile sampler with a gradient as input and lay those over the cells you get from it.