UV's in Maya and Max

ajv3d

Hi everyone. I have a second UV channel for each object in my scene for light mapping. I'd like to combine all the second UV channels for each object into one UV Map to lightmap my whole scene.

I know Maya has better options to copy UV channels within the UV Texture Editor, but what is the best way to get different objects on the same map in Max?

It seems saving the UVs and loading them into the second channel for each object works for individual lightmapping. BUT, what's the best way I could combine every objects second UV channels into ONE map? ...without using 3rd party software or plugins.

Rick_D

have you tried selecting all the objects, applying an unwrap and changing the channel to 2?

ajv3d

No, I didn't even think about that. I'm still getting use to modifiers inside of Max. I didn't think to add a single modifier to all objects at one time. If I already have saved UVs for all my objects, I'm assuming I can just load them all into the UV unwrap modifier that contains the whole scene?

Rick_D wrote: »

have you tried selecting all the objects, applying an unwrap and changing the channel to 2?

Mark Dygert

Nope, it's going to make a mess. Load the UV's for each individual mesh first, then select them all and apply Unwrap UVW, then switch the channel to 2, hit reset and you're good to go.

It can be helpful in this case to move and separate the UV's on each individual mesh so they won't stack when combined. You can also assign a unique material ID to each object and use the lower filter box in the UV editor window to display only that material ID.

Why loading the UV's after the fact won't work:
Each vert is given a number and position. If you edit a group of objects all the verts are given new numbering since you can't have 6-7 verts called #1. When you load a UV layout, its going to put vert1 in whatever position it finds in the file. It doesn't know that these collection of verts over here are a drain pipe and those over there are a hand it will more than likely take a few verts from each object and arrange them in a way that looks familiar, until you click on the faces and see that what it put in the drain pipe was actually faces from the hand.

You can only load and save layouts between the same objects only if the vert numbering hasn't changed. Any time you add or remove geometry, OR attach or detach geometry, the vert numbering changes.

ajv3d

Really good information, thank you. Does Max have a layout feature to uniformly layout your uvs like Maya? This way once I select all the meshes I can lay them out in 0/1 in one shot without needing to place all the shells by hand?


[/B][/B]QUOTE=Mark Dygert;1355196]Nope, it's going to make a mess. Load the UV's for each individual mesh first, then select them all and apply Unwrap UVW, then switch the channel to 2, hit reset and you're good to go.

It can be helpful in this case to move and separate the UV's on each individual mesh so they won't stack when combined. You can also assign a unique material ID to each object and use the lower filter box in the UV editor window to display only that material ID.

Why loading the UV's after the fact won't work:
Each vert is given a number and position. If you edit a group of objects all the verts are given new numbering since you can't have 6-7 verts called #1. When you load a UV layout, its going to put vert1 in whatever position it finds in the file. It doesn't know that these collection of verts over here are a drain pipe and those over there are a hand it will more than likely take a few verts from each object and arrange them in a way that looks familiar, until you click on the faces and see that what it put in the drain pipe was actually faces from the hand.

You can only load and save layouts between the same objects only if the vert numbering hasn't changed. Any time you add or remove geometry, OR attach or detach geometry, the vert numbering changes.[/QUOTE]