need help with Ac3D

[Reborok]

Hi
can somebody help me
i often heard that ac3d is used for games
how do you want to use ac3d character without bones???
i don´t know if there is a plugin for bones or something else
can somebody help me, i need help, REALY

i hope that somebody can help me and is going to write me

reborok :grin:

[lisa]

Cool. Are you writing your own game, or making a mod?

Just for clarification: are you asking how to rig a model for animation using AC3D, or how to create animation keyframes with AC3D?

AC3D doesn't have the ability to create animation keyframes; you'll need to use an external program like Poser if you're wanting to create keyframe animations.

However, AC3D can be used for basic animation rigging and is useful for games that use procedural animation instead of keyframe. i.e. Most racing games don't animate the cars in advance, they do it in real-time using physics equations instead. AC3D can be used to create and setup models for many of these types of games.

Bones are only needed for soft-body animation (i.e. deformable characters) because of the blend weights. For rigid body animation (i.e. vehicles) a simple hierarchy and pivot points for each mesh are all that are needed for many setups.

You can access the Hierarchy View in AC3D from the Tools menu. Object centers can also be set on the Tools menu.

---------------------------------------------

TECHNICAL SIDE NOTE FOR PLUG-IN DEVELOPERS AND THE CURIOUS: Although AC3D doesn't have native support for blend weights, I've actually been using it to rig deformable models by using either a texture map as a weight map, or more commonly by using overlapping vertices and then just merging the verts and dividing by the number of overlapping vertices to get the blend weight in my exporter. Painting a weight map is of course the more refined way to do it, but even the overlapping vertices method works surprisingly well for simple characters.

[luuckyy]

I'm not a plugin developper, but I'm curious for sure ...
Please can you explain what is a weight map ?
How do you use it ?

using either a texture map as a weight map

I just can't visualize that.

There's so many things to learn in the 3D field, that I will be dead before then end of the learning course

[lisa]

Originally Posted by luuckyy

Please can you explain what is a weight map ?
How do you use it ?

Sure thing!

A weight map is a grayscale image that is used to blend smoothly between two effects. The effect could be a material, a deformation, a transform or any number of other things, but the most typical uses are materials and vertex bone weights. Any pixels that are black in the weight map use the first effect, and any pixels that are white in the weight map use the second effect. For example, if you were using a weight map to blend between a red and a blue material, black pixels in the weight map would turn the object red, blue pixels in the weight map would turn the object blue, and gray pixels in the weight map would turn the object purple as it would mix the red and blue together.

Using a weight map for bone weights works the same way. Remember, a bone is really just a transform. For example, a leg "bone" is a transformation matrix that stores the pivot point and rotation of the leg. The pelvis "bone" is the pivot and rotation of the pelvis. If you wanted to blend the vertices in a character's hip between the leg and the pelvis you could use a weight map to indicate which vertices were influenced by which; so that vertices near the thigh are almost entirely influenced by the leg, and vertices near the waist are almost entirely influenced by the pelvis, and vertices in the middle are blended between the two.

How many and what kind of weight maps you need depends on the specifics of your renderer. Many renderers need one weight map per bone, to indicated the strength of the influence of the bone on the different vertices of the model, bt other possible combinations exist.

[Reborok]

thanks for help
it will be very interesting to learn more about ac3d
first i´ll use poser, than i can write a new message if i need help, more help

Reborok

[Reborok]

hi
i am here again who else???
i have just 1 question more...
wich vision of poster should i take 1, 2, 3, 4, 5, 6, 7...
i hope u will help me
Reborok

[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! )