3ds max and texture baking questions

I've been trying to learn more about texture backing in 3ds max and there is a good tutorial in the manual called "Rendering to Texture". They take a biplane with this texture here
http://www.therefrisky.com/archives/biplane1.jpg

They then add a light or two which adds the shadowing, and the texture gets baked to this output.
http://www.therefrisky.com/archives/biplane2.jpg

I'm not sure what to do at this point or even if it is technically possible. How can the rendered texture file be reassembled into the shape of the original texture, so it can be normally mapped onto an object?

thanks for your time.

Twid

I don't know how it's done in Max (I'm on a Mac,) but in LightWave, when you bake a texture, you can choose what map to bake it onto.

I just bake 'em onto the map provided by the Lindens, and there it is!

Well you wouldn't do something like max's biplane example because there's no way to replicate the biplane model in SL with the same UV mapping. But... the primitives in max do have the same UV mapping as the prims in SL so what you'd do is build something in max out of primitives, texture it, light it, and then use render to texture to output baked textures for use recreating it in SL. For anything but a sphere the easiest thing to do is split them apart so that each surface is a unique object. Make sure when you use render to texture that you set it to use the objects existing UV channel 1 instead of generating new UV's with the auto-unwrap function.

Chip, can't you bake the texture onto the AVs in Max?

For that matter, can you choose what map to bake onto? Or have more than one map associated with a model?

In LightWave, you can take the texture from one UV Map that is associated with a model, and bake it onto another. That's mostly what I do, (although I do bake prims now and then.)

I guess I just kind of assumed it was the same in all the major programs.

Now I'm really curious.

Yes, you can do the same things in max For working with the av model it can be useful to remap with custom UV's and then bake back to the original UV's. For baking intended for use on prim builds that ends up being more trouble than it's worth since max's and SL's prims are mapped the same way. The reason I suggest splitting prim surfaces into unique objects in max is that you want to end up with a unique texture for each surface but the UV mapping isn't set up that way. Cubes repeat the same texture on each side, cyllinders repeat the same texture on the curved surface and end caps, and so on. When baking normally in max it avoids that problem by automatically creating new UV's set up like texture sheets. To use those in SL you'd need to take them into an image editor and split them apart which is a bigger pain in the behind than just treating each surface like a unique object to begin with.

Ah! Good. I thought so.

In LightWave, I'd just put each side of the cube on its own layer, to get the program to burn six separate images.

That's how I get it to burn the cuffs and collars onto their own images, even though I'm using the same UV Map for the whole AV.

Interesting.

Thank you for the great tips Chip. Finally after banging my head on the desk for 3 days, I was able to make a texture burned skirt. Woohoo! I know this must sound so basic to 3ds experts, but it just seems so hard to noobie me. lol

I've attempted to move onto avatars and now there are new roadblocks. I tossed the skirt tga onto the top of the body, just as a test and rendered it. The results are all fragmented. Can you tell me how to stop this fragmentation? Here is a screen cap of what I was trying.

I notice that in the model the shoulders are not attached to the mid section. I think I can manually link the textures in photoshop for now, but is there a way to somehow link these two sections so only one texture pulls off, just like in game?

thank you kindly for your time

Twiddler

I have Max (maya too). So you're saying you want to burn texture's onto an AV, yes?

BTW- you can create separate maps for each side of a cube in Max. Gotta take a look to remember how tho.

Hmmm, I don't think that is exactly what I meant. Here is what I would like to do...

1. Open a female model
2. Place a shirt texture from SL on her
3. Add lights to the 3ds scene
4. Render the Texture
5. Now upload the new baked texture to world

A fast and easy example to help visualize this would be...toss a pure black texture onto the model in 3ds. Add lights and gloss and reflection to the scene. Bake. An instant latex catsuit.

Another example would be to toss skintone onto the model, light the scene, bake, and now you have a nicely shaded skin. This procedure is less artistic than hand painting, but would have interesting results. I'm too noob to understand how to do it or even if it is possible.

Any tips or ideas that would help me get further or improve? Thank you for the help.

Twiddler

There's a couple of things you need to do to prepare to avatar model before it's useful for baking. The avatar is split into several pieces according to the way the vertices are assigned to the various bones in Poser. That will interrupt the polygon smoothing and cause visible seams when rendering to texture.

Here's what you'll need to do to prepare the model for baking in max:

1. When you import the obj file you want to make sure the import options are set to "single" instead of "multiple." That will bring in all the parts of the avatar as elements in the same editable mesh. Set the vertex scale to 125. That will bring the avatar model in at just about six feet tall (or about 70 generic units depending on what unit system you're using). The scale is important because you're going to need to weld some vertices together and if you imported the model with a vertex scale of 1 you'd end up welding more of them together than you want because you wouldn't be able to set a low enough weld threshold. The scale is also important if you plan to use radiosity or global illumination which work best at real world scales.

3. The avatar model is split up into various pieces that relate to how the vertices are assigned to bones in Poser and SL. This isn't very useful for purposes of 3d paint or texture baking so we need to take care of that before it'll work well for baking. Some of the parts will probably import with their polygon normals flipped the wrong way (they'll appear inside out). To take care of that go into subobject elements mode and select any flipped parts. Scroll down to the surface properties section on the modify panel and hit "flip" to reverse the normals. When all the parts look correct go to the next step.

4. Now we need to get rid of the seams between the various parts. Go into subobject vertex mode and select all. Under the "edit geometry" section of the modify panel set the weld threshold to a very low value (like .001). Zoom in one of your viewports to the most detailed part of the model (around the eyes and nose). When you weld you want to make sure you're not accidentally welding vertices together that you don't intend to. We only want to weld the duplicate vertices along the seams. If when you weld you notice any vertices collapsing together that aren't supposed to, undo and set a smaller threshold value. The threshold value is set in the numerical input next to the "selected" button. When you're ready to weld, click that button.

5. Next you want to smooth the polygons so they shade correctly over the seams we just eliminated. Go to subobject element and do a select all. Scroll down to the bottom of the modify panel under smoothing groups and click smoothing group 1. Now there'll be smooth shading across all polygon edges.

6. The next part is optional depending on what you plan to do. You may find it useful to have the model be one piece, or you might prefer to divide it into seperate pieces along the texture seams. Of you might want to use multi-subobject textures and just assign a different texture ID for head, upper body, and lower body. Right now those three parts all share UV channel one so if you bake you'll end up with them overlapping each other on the baked texture. Take the SL upper body template and make a texture out of it. Assign it to your model and make sure you have it set to show the texture in the viewport. This will let you see where the seams are between the three texture templates. I'd clone the model so you'll still have one that's all one piece if you need it later. Hide the cloned one to get it out of your way. Go into subobject polygon and select all the lower body polygons up to the waist seam. Then detach them to a seperate object. Do the same for the head polygons above the neck seam. Now you can bake individual textures without having to worry about having overlapping textures.

Now you should have much better results