Highlighting sharp edges?

Valandar

Just out of curiosity, is there a method of highlighting the edges of an object? I have more than a few models with mechanical edges (delineated by bevels, unfortunately, not really sharp angles) where I need to align 'paint chips', and doing it the old fashioned way is highly tedious, especially where I have to match seams.

I guess what I'm looking for is pretty much the opposite of a cavity map... Any suggestions?

arshlevon

you can do it in crazy bump, i go over it a bit here
look at the bottomish pics the one at the top is old way, just more steps and it involves photoshop more.
http://boards.polycount.net/showflat.php?Cat=0&Number=275885&an=0&page=0#Post275885

the example i give dosent really show off how useful it is for mechanical stuff, but give it a try and see the magic.

Valandar

Erm... I have no map to use.

I mean on actual hi-res objects, not maps the kind I make for my "day job". I have to texture a series of objects like worn, painted metal, and would really like to be able to "spot" sharp edges on a UVMap pretty quickly.

I have no base normal or anything map to use for this kind of calculation.

Would it work if I inverted the normals, and rendered an AO map, for example? Or would I just end up with everything pitch black?

EarthQuake

Um, that would be the same as inverthing the ambocc map wouldnt it? o_O

Valandar

No, if I did, then the entire surface of smooth plates, where I do not want the chips, would be black, not just the corner edges.

arshlevon

what 3d package are you using?

you could always use a pits and peaks type plug in that will make the peaks white and the pits black in your vertex colors, bake that to a texture and refer back to my tutorial to the levels adjustments to get your desired result. once you have that you can just copy in an alpha channel and load the selection anytime you want.

Valandar

Using 3DS Max actually.

Eric Chadwick

Hand-painting them wouldn't be too hard.
http://forums.cgsociety.org/showthread.php?f=46&t=373024

If you're working in Max, you could select the edges you want, then use Texporter set to render Only Selected, which would render a wireframe of the selected edges.

F-edge might also be a solution for Max. I haven't used it though.
http://www.ddag.org/products.htm

Slum

Mike Voeller's Find Edges script will save the day!

http://www.squirrelyjones.com/public/find_edges.mse

Valandar

Thanks, I'll try it out!

Valandar

Looks like "Pits and peaks", the script mentioned by Pior in the second post in this thread:

http://boards.polycount.net/showflat.php?Cat=0&Number=281898&an=0&page=0#Post281898

is the one I want. Thanks, guys!