need help with Ac3D

[luuckyy]

Thanks for the infos Lisa !

You seem to be a very good 3D technical honestly.
I already was aware of vertices weights in an animation work for smooth animation purposes, and I've made some use of that sometimes, but that weight map ... this is the first time I see that.

2 other questions if you don't mind :

- How do you create a weight map ? I mean, I know how to create greyscale pictures for bump maps, and b/w pictures for opacity maps, but ... are you "painting" black vertices and white vertices on a grey background for a weight map or ... ? If so, how can you be accurate in this job ?

- What softwares make a use of these weight maps ?

TIA

[lisa]

Originally Posted by luuckyy

You seem to be a very good 3D technical honestly.

Thanks. I write graphics engines and simulations for games and film for a living, so I get a lot of practice.

Originally Posted by luuckyy

- How do you create a weight map ? I mean, I know how to create greyscale pictures for bump maps, and b/w pictures for opacity maps, but ... are you "painting" black vertices and white vertices on a grey background for a weight map or ... ? If so, how can you be accurate in this job ?

It depends on the software. Some let you color on the vertices, like vertex painting in Blender.

For others, including AC3D, you just UV map the object, and then paint the weights in a grayscale image like any other texture. If you save your template with the "Copy image to clipboard" feature in the texture coordinate editor, it'll give you something to paint over, and then it's not too difficult. You don't need to be terribly precise - I just airbrush over the whole region in PhotoPaint and blur to keep it smooth.

Originally Posted by luuckyy

- What softwares make a use of these weight maps ?

Lightwave, Maya and SoftImage all use weight maps, as do some other high-end tools. Here's a Lightwave tutorial to give you some idea how they do it: http://www.geocities.com/rgkovach/wp_tut.htm And another one for Max: http://mxmgallery.maxwellrender.com/wmap_en_vr.pdf

In my case, I'm targetting my companies' game engine, which is it's own custom renderer.

POV-Ray also supports weight maps, although AFAIK only for materials. POV doesn't call them weight maps, it calls them "image_pattern" instead, but it's the exact same concept... you can use a grayscale image to smoothly blend between two textures.

[lisa]

"Slime Cube" modelled in AC3D with soft-body deformations from weight maps:
http://download.tenfootpolesoftware....-turntable.wmv

(Please ignore my crappy video capture job! )