The Dirt Node is driving me mad!

[gordonrobb]

I know I had other threads, but wanted to make sure this one was in here.

Title says it all. The dirt node is driving my mad. I'm trying to use it to simulate edge wear. I've managed it and seen examples of it elsewhere, but there is however a series of problems with it.

Firstly, the problem with the fact that using it makes any low res geometry show up edges where you dont what them to show up - this was fixed (kinda) with the tolerance (I think it's called) parameter.

Secondly was the fact that there wasn't enough contrast between the black bits (on the edge) and the white bits (on the flat) - fixed (ish) managed to figure out now to increase the contrast with a colouradjust (I know that's not what it's called) node. Has it's own problems as it makes the edge darkness shrink a bit more than I'd like, so you have to then adjust the dirt node to compensate. This is however workable.

Lastly however, and this is the one that is driving me nuts, and took me ages to verify. The node behaves VERY differently depending (it would seem) on the thickness of the object, and how big the polys are that it is on. Look at this image.

The grey-ish stuff is all using one texture. The bit that I have marked "1" is a solid bit This is about what I want it to look like (I have not applied any contrast yet to make the lighter bits white, and the darker bits black). You can definitely see the effect is focussed on the edges. However, the bits marked with a 2 (same material) behave completely different. All of these bits, while solid, are thin. I can't make them solid, as they all have insides.

Any help, advice, psychological help, (or more likely fixing the node so that thickness does not affect it) would be greatly appreciated.

[roeland]

I think it will behave better if you use a higher details setting.

--
Roeland

[FrankPooleFloating]

Gordon, without knowing your level of expertise, I would say that if you have a good UV that has islands that are meaningful and easy to tell what is what, use something (xNormal etc) that can bake a nice AO of this bad-boy and do this dirt by hand. Once you have a good ambient occlusion (and possibly cavity map too if you can) in PS, it is not terribly difficult to make some sweet-ass dirt. And if you have dDo or Substance Designer, even better. Those do 90% of the work for you. I know from experience that dDo would put dirt and scratches on this bastard that would absolutely knock yer friggin' socks off...

Funny.. dDo just got an update to 6.0 for registered users and they are now making 5.3 free for anyone else... but Quixel's site is down because they are apparently updating the site and officially launching new dDo and nDo (normals plug) for GDC, which I think started today...

[gordonrobb]

I think it will behave better if you use a higher details setting.

--
Roeland

The Details setting makes a difference, but the problem (the panels being dark, rather than the edges) is only affected by the distance control. It has to be set low enough that its not affected by the thinnes of the panels. Therefore also affecting how far from the edge the effect shows.

[gordonrobb]

Gordon, without knowing your level of expertise, I would say that if you have a good UV that has islands that are meaningful and easy to tell what is what, use something (xNormal etc) that can bake a nice AO of this bad-boy and do this dirt by hand. Once you have a good ambient occlusion (and possibly cavity map too if you can) in PS, it is not terribly difficult to make some sweet-ass dirt. And if you have dDo or Substance Designer, even better. Those do 90% of the work for you. I know from experience that dDo would put dirt and scratches on this bastard that would absolutely knock yer friggin' socks off...

Funny.. dDo just got an update to 6.0 for registered users and they are now making 5.3 free for anyone else... but Quixel's site is down because they are apparently updating the site and officially launching new dDo and nDo (normals plug) for GDC, which I think started today...

Totally happy with painting textures myself. However, this is all one big experiment in trying to create procedural materials. If I can do that, it's a drag and drop onto a new object, without having to UV and or paint. Also, the dirt isn't the object. The dirt node, in normal mode works completely as expected. It finds the crevices and darkens them, based on the parameters. It's when you use 'invert normals' to work on the edges (which is what I'm trying to do) that the problem shows itself.

[FrankPooleFloating]

Aaaaaah.. roger dat.

[gordonrobb]

Found a solution in one part. On the panels that you don't see the inside of (front of the tractor) I can just delete the inner polys and it works (Yay). However, you can see, things like the door (which I can't delete the back polys of, or you'd see that through the glass) or thin parts, you can see the problem is still there. So would love a way to not have the back geometry affect the calculation.

And Frank, this is the kind of thing I'm aiming at. Totally procedural, (except a scratches image). It's a bit over board compared to what I'm aiming at, but shows what I mean.