View Full Version : photo real toothbrush bristles

06 June 2006, 06:10 PM
I need to model photo real toothbrush bristles. No matter what I try I cant seem to get the right look. Iíve tried using xsi hair geo shader and making hair from polys. Can anyone please help me out?

06 June 2006, 06:18 PM
Here is what i did, and it looks nothing like the photo

06 June 2006, 06:40 PM
You need a specular highlight and try to create a little more unequal distribution between the bristles. Have a few stray bristles portruding by their lonesome.

You could try a cylinder for the large pieces and use a texture to create the specular highlight or maybe just use a bump map for the whole cylinder.

06 June 2006, 08:25 PM
You could also try using hair/fur for it, and or also using SSS in addition to what ever other method you choose.

You should be able to ge there with incident nodes and gradients along side some spec settings.

06 June 2006, 08:48 PM
If you have hair available to you (or BenR's plugin) you could get very close using the muhHair shader. Those bristles are very much like hair in terms of light interaction.

06 June 2006, 04:50 PM
I agree with JDex, MuhHair is great for things like hard bristles...XSI Hair creates a look that is too soft for bristles.....

06 June 2006, 08:07 PM
A few years ago, before there even was hair in XSI, I worked on a national spot for Oral-B using XSI. Obviously, we had to get everything looking as photoreal and accurate as possible, since our clients were serious, German, toothbrush engineers who would get offended if you called them "brisltes" instead of "tufts". :)

The thing about tufts is that they are monofilament, plastic tubes. They are transparent and translucent, and have a lengthwise, anisotropic, specular streak with distortions. The thing about hair geometry is that it is flat, and all of the shading tricks it uses start from flat geometry. You could displace each hair fiber into a half-tube using a black-white-black gradient applied to a barycentric texture space (barycentric is a setting found on the vector state node, I think) but then it's still only a half tube facing camera. To get the proper translucency and volume effects, you'll need tube geometry.

So hair instancing NURBs tubes would be one way to go. Another would be to build and rig actual tubes, which is what I had to do, not because of shading issues, but because we had to animate our toothbrushes a very specific way.

Good luck!

CGTalk Moderation
06 June 2006, 08:07 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.