maya 2008: bake gradient into vert colour

rooster

how do, I'm looking for some way to bake colour into verts along some geometry, with the colour gradiating as x increases. any ideas?
first try baking using lights didn't really do the trick, any sides of the geom were overblown because they could be hit by all nearby light. I need it to be pretty much projected from z..

any ideas?

Michael Knubben

Do you have a gradient material-type in maya? If so, set up the uv's so that goes along the geometry that you need, and bake that down to verts?

malcolm

MightyPea has it right, there is also that vertex chameleon tool which has a vertex gradient tool.

Lamont

If you want to transfer just color (from the diffuse image)

1 - Render Settings > Common > Turn the Default Maya light off...
2. Color> Batch Bake Mental Ray Options > Light and Color then make sure you have it set to "Bake to vertecies".
3. Start baking

If you're really going to get deep into this, a good thing is to have lights with proper falloff. Then if you want to bump color up or down, just bite the bullet and start grabbing faces and apply color.

rooster

gradient colour baking is proving to be a pain, because the vert colour bake doesnt seem to work with secondary UV sets. I need the main UV set intact..

Ideally what i want is verts hit by light to be lit regardless of normal, so faces sideways on, or backfacing are lit all the same.

But, I can't fuck up the normals because I need to be able to bake ambient occlusion into the vert colour too..

edit: lamont: if I do use lights, how do you reckon I could get around the problem of sides of geom being blown out? I really want the sides to be exactly the same colour as the front at the edge

could I do something with image based lighting I wonder?

edit: ,malcolm, checking out vert chameleon

rooster

hurrrr. ok vertex chameleon has a nice gradient tool: problem is it applies per object, and I need it over a bunch of objects (did I mention that )
If I combine them all, works fine, but I need them seperate. seperate command clears vert colour. how handy! I can't believe it still fuckin does that

also, trial is only 15 days.. I don't think I'll convince management to buy something just for this, so free would be an ideal solution

Sa74n

did you try grouping the objects instead of combining them? not sure if that works though

Lamont

Ideally what i want is verts hit by light to be lit regardless of normal, so faces sideways on, or backfacing are lit all the same.

Use Color > Prelight Maya.

I like to use volume lights when I just need an area of color and no light direction. It has a fall off from the center by default, you can change this.

Lamont

I hope this is the effect you're trying to achieve. If you notice the bottom example, the power of the lights dropped as I added more. (I bumped the light scaling factor in this one). You're gonna have to adjust for that. Also, Maya only does 8 lights at a time.

Better example of it ignoring face direction:



And they come in different shapes.

rooster

thats perfect man! using the square area light I got exactly what I need, and it's nice and flexible. Mucho gracias senor

edit: hey man, you don't know how to get the 'down axis' option working on the volume light do you? I'm trying to use it but it just works as a point light anyway

Lamont

rooster wrote: »

hey man, you don't know how to get the 'down axis' option working on the volume light do you? I'm trying to use it but it just works as a point light anyway

That's pretty much what happens when you put that option. It acts more like a directional source.

rooster

yeah I want it to behave directionally, so all light in the area comes from x to negative x, but the light just comes from the center of the gizmo with the option checked.. I can't notice any difference using that option to the normal mode

there's an arrow that appears when you set it to that, but I can't see the bake picking up that direction.. makes me wonder if the bake isn't picking up the setting

Lamont

I never use that because the results are wonky. I just use the light with the gradient falloff.

Also, imagine that you're enclosing things in a light mass, so not much difference will be seen.

rooster

ah well.. another maya feature that doesn't quite work with another maya feature

in the setup I have there is quite a difference, I want a long strip of stuff to be gradient lit from back to front evenly, so the directional light parameter would have been perfect. with the point light behaviour I guess I'll have to put rows of area lights behind the geom, but where the falloff overlaps there's inconsistency with the gradient. I also seem to notice that the more area lights I add, the darker the overall bake gets

best solution I've got tho


just had a thought: is it possible to get that 'ignore normal direction' type of lighting outside of maya bake? like in a normal render?

rooster

Think I've cracked it.. I got the area light to behave that way by unchecking diffuse and checking ambient in the light, using cylinder and along axis light mode.

using mental ray bake, I can get the right results..
Cheers everyone who replied!