mulit\sub object material with multi uvws
Hello,
I'm having an issue with max 9 using multi/subobject materials with multi uvws.
I created a test (I don't know that much about multi uvs, and multi materials) with one model. I changed the poly id's on the parts that I wanted to have a different map, with different uvs. Then I added a unwrap uvw one with map channel 1, one with map channel 2. made the uvs for the two, coresponding the different poly ids. Then I set up a multi sub object material with the 2 textures (both also changed the channel acorrdingly) and applied it to the model.
It worked fine. respected both sets of uvs. Great!
Now I've tried duplicating that process on another object. And it doesnt work the same.
It uses the 2 different materials (following the poly id's) but it only uses the uvw coordinates from the Unwrap Uvw with the map channel 1. it ignores all other uvs with different channels.
I'm assuming I'm missing a check box, or haven't set it up just right.
Does anyone know what I'm doing wrong?
Thanks!
I'm having an issue with max 9 using multi/subobject materials with multi uvws.
I created a test (I don't know that much about multi uvs, and multi materials) with one model. I changed the poly id's on the parts that I wanted to have a different map, with different uvs. Then I added a unwrap uvw one with map channel 1, one with map channel 2. made the uvs for the two, coresponding the different poly ids. Then I set up a multi sub object material with the 2 textures (both also changed the channel acorrdingly) and applied it to the model.
It worked fine. respected both sets of uvs. Great!
Now I've tried duplicating that process on another object. And it doesnt work the same.
It uses the 2 different materials (following the poly id's) but it only uses the uvw coordinates from the Unwrap Uvw with the map channel 1. it ignores all other uvs with different channels.
I'm assuming I'm missing a check box, or haven't set it up just right.
Does anyone know what I'm doing wrong?
Thanks!
Replies
You are doing everything right except one thing. After everything is modeled and UV'd you need to go into 'Element' mode and select the pieces you want to have a different material on it, then you click 'Detach'. This will help you go over the UVW without it being interfered with the original mesh's UVs.
From there you unwrap the detached pieces by themselves- take it into photoshop, then texture it normally. After you have your (Diffuse, Spec and Normals...) go back into the Multi/Sub Object in 3ds Max. Set the Id numbers to "2" or however many materials you have. then go into your second material as you are used to then click it- go to diffuse, click it - bitmap: select your maps and apply it.
Then click the return or up button to go back to the main 'Multi/Sub object' apply it ALL as a whole onto the entire mesh (drag select everything). Offcourse from there some stuff will be missing. Attach the separate mesh pieces that you unwrapped separately together. FROM there you use the Poly ID setup.
Hopefully I wasn't too confusing, good luck!
You don't need multiple UV channels unless you're combining two maps in a single material, and each requires a different UV layout.
A good example is lightmapping (see Pior's example at the bottom here) where the color map uses a UV channel optimized for UV space with overlaps and mirrored bits, but the lightmap uses a 2nd UV channel where every triangle has unique space in the map.
That was originally what the explanation was for- sorry If I misread your question.
I did want multiple uvs, because I have multiple maps. I figured this was the best way to do that (?). If I understand correctly from the example, pior had 1 object with each polygon being uv-d twice. so same polygon - 2 uv coordinates (right?).
Where as I have 1 model, each poly with 1 set of uv coordinates but with different textures, and materials.
So really, should I just be using 1 uv channel, with multiple material ids.
My apologies for the miscommunication. I had no idea that you could have 1 polygon with 2 uv coordinates. I just assumed that multiple material ids, with unique materials and textures needed multiple uvs (channels). (Saw it and though, "what else would that be for other than...?!"
Sorry again, and thanks for the help!
EDIT: What pior did was for baking "fake shadows" without the need of present dynamic lighting. Pretty much can be used for handpainted textures since you have to create the highlights and shadows from scratch. So many uses for it, but to answer your question: After you have unwrapped your mesh- you will notice that sometimes you overlap your UVs to save space if some sides on a mesh are symmetrical. You right click on the modifier, then click 'Collapse All'. Then re-open the modifier list get UVW...from there instead of the number "1" uv channel, move it up to "2"
From there, pack all the UVs, make sure nothing overlaps and from there you can do what Pior did. The reason why you bake shadow maps on the second channel other than the original one- is so it comes out clean without any weird artifcats like it would if you baked it through UVW channel 1.
One reason to use a M/SO is to make the hair with a material that has opacity, while the rest of the body doesn't have opacity, because opacity is generally expensive in a game engine, so you want to reduce how much of the model uses it.
Another reason to use a M/SO is to use a different set of textures for one part of the mesh, than for the rest of the mesh. So for example if you have a character with team colors, the colored bits could be on a different texture from the rest of the character, so that texture could be swapped out to change teams. But even then it's generally better to use single texture sets where possible, because it's less expensive in memory and it generally renders faster (because of batching). The graphics programmer for your game is going to want you to be efficient.
You only need multiple UV channels if you are using more than one map in the same material, and those maps also need different UV layouts (like color map vs. light map). When this isn't the case, use a single UV channel instead, because the less UV channels you use, the less expensive the game model will be. More UVs = more memory.
Right.
Thanks again!