Procedural paint chips

Valandar

A while back, there was a thread that I THINK was here (either here or at CGTalk and I couldn't find it there, either) that linked to a tutorial that detailed a method for procedurally generating a paint chip mask in 3DS Max. Can anyone else remember it?

EDIT: This was the result, just as an example, and it could produce variable size and amount of edge chipping:

Ben Apuna

Was it this one?

Valandar

YES! That is EXACTLY what I have been looking for. Bookmarked and thanks proffered!

kodde

Sorry if this is a bit OT. But wouldn't a alternate way to find these areas to add the chips be to compare world normal of your mesh between each other? Throw in a tolerance threshold and you should be able to pick up depending on how hard your edges are.

konstruct

coooool

Mark Dygert

kodde wrote: »

Sorry if this is a bit OT. But wouldn't a alternate way to find these areas to add the chips be to compare world normal of your mesh between each other? Throw in a tolerance threshold and you should be able to pick up depending on how hard your edges are.

That would be interesting. I wonder if you could add some kind of ray projection from the normal to see if anything was hanging over or protecting the edge. That way you don't get chips and dings in areas that don't make sense. Probably would need some kind of external script that ran outside of the shader and fed it some kind of input...

At the bare min you cause it as a place to start, render it out and just paint out some of the chips.

Yea Neil never disappoints.

Eric Chadwick

kodde wrote: »

compare world normal of your mesh between each other? Throw in a tolerance threshold

Cavity map, inverted, thresholded?

kodde

EricChadwick wrote: »

Cavity map, inverted, thresholded?

That's what I was thinking. Tried playing a bit with it this morning but didn't get it right, almost got there. At least the masking edges part. Might play a bit more with this.

If you guys try any of this and get some results then please share your insights

Valandar

I just used this technique, baked it out, then painted over inset areas that wouldn't get chips.

Maybe a variant on the Pits and Peaks script would work for finding the edges better?

Mark Dygert

You could also probably add another noise/chip mask to the the white part of the blend to get some chips along the large blank areas, since its not only the edges that could have dings. But it might be easier to clone a few chips where you want them instead of paint out all the chips you don't...

Valandar

In this instance it was a relatively simple shape - not that many areas that showed chips that didn't need them. But in more complex shapes you might be right.