Using Multiple Map Channels to Make Decal-like materials problem.

[Anonymous]

How do I go about doing this? I'm juggling a lot of things and already facing re-uving my model which is okay, but I don't want to hit the same dead end and have to do it again.

I've got a car that has a lot of ins and outs, so it takes some thought as to where I want to split it up, but two parts need to have decals, the hood and the rear flat tail light section. My last mentor talked at length about Map Channels, but I wasn't quite there yet.

My plan is to create a composite material, and have 3 of the layers contain the decals and composite them together. What I would really like, ideally is to have the entire car body, hood and everything on Channel 1. Have an optional Channel 2 with the Hood UV's larger so someone can add markings. Have an optional Channel 3 with a larger tail section for markings. Here's another desire that led me to this: The hood section needs high res bump for some panel lines.
I'm working hard to condense my materials and textures needed, and having one material do all these things would be awesome. (prevent making a whole other material for the hood.)

Step 1: So what I do, is split the car up into nice UV's using map channel 1.
Step 2: (I can't think of any way to do this right) I add another unwrap modifier and select the faces I want, hood and tail) I collapse to Editable Poly.
Step 3: the polys from unwrap uvw are still selected, so I add another unwrap with only those selected and set that to Channel 2. It actually seems to work. But if I try to add a Channel 3 or 4, things go screwy, and that's where I am now. By Screwy I mean that the map channels stop working, the textures stop going to the right channels, the channels seem to reset... honestly not too clear what I'm even doing.

I hope this is making sense. What I'm essentially trying to do is have one material, but have multiple decals at good resolution on that material, with a side benefit of being able to change those decals.

I see a lot of tutorials about map channels, but they are usually using planar over planar of the same size on one face, and not really making big changes. I've gotten this to halfway work, but I feel I'm not understanding the fundamentals 😞

Also, is there a way maybe in UVW Unwrap where you can flip through your different channels?

[Anonymous]

How do I go about doing this? I'm juggling a lot of things and already facing re-uving my model which is okay, but I don't want to hit the same dead end and have to do it again.

I've got a car that has a lot of ins and outs, so it takes some thought as to where I want to split it up, but two parts need to have decals, the hood and the rear flat tail light section. My last mentor talked at length about Map Channels, but I wasn't quite there yet.

My plan is to create a composite material, and have 3 of the layers contain the decals and composite them together. What I would really like, ideally is to have the entire car body, hood and everything on Channel 1. Have an optional Channel 2 with the Hood UV's larger so someone can add markings. Have an optional Channel 3 with a larger tail section for markings. Here's another desire that led me to this: The hood section needs high res bump for some panel lines.
I'm working hard to condense my materials and textures needed, and having one material do all these things would be awesome. (prevent making a whole other material for the hood.)

Step 1: So what I do, is split the car up into nice UV's using map channel 1.
Step 2: (I can't think of any way to do this right) I add another unwrap modifier and select the faces I want, hood and tail) I collapse to Editable Poly.
Step 3: the polys from unwrap uvw are still selected, so I add another unwrap with only those selected and set that to Channel 2. It actually seems to work. But if I try to add a Channel 3 or 4, things go screwy, and that's where I am now. By Screwy I mean that the map channels stop working, the textures stop going to the right channels, the channels seem to reset... honestly not too clear what I'm even doing.

I hope this is making sense. What I'm essentially trying to do is have one material, but have multiple decals at good resolution on that material, with a side benefit of being able to change those decals.

I see a lot of tutorials about map channels, but they are usually using planar over planar of the same size on one face, and not really making big changes. I've gotten this to halfway work, but I feel I'm not understanding the fundamentals 😞

Also, is there a way maybe in UVW Unwrap where you can flip through your different channels?

[10DSpace]

Hi @Anonymous 

Personally, I think an easier workflow is to work within a single instance of the Unwrap UVW modifier on your car model.  In combination with assigning a multi-subobject material to the car model, you can do what you want to do.  In other words, I would NOT use a composite material as you are trying to do, but instead use a multi-subobject material on the car model.  I don't know what version of max you are using, but I'm pretty sure the feature to assign and select polygon ID's from within the Unwrap UV Editor has been available for some time now.  So if you have already setup all of your polygon ids the way you want, you can select these polygon ids for further UV editing or selectively display the UV's by selecting the ID you want in the dropdown list (see below):

What I'm essentially trying to do is have one material, but have multiple decals at good resolution on that material, with a side benefit of being able to change those decals.

In essence, with the above approach you have a single-Multi-SubObject Material  for your model and you can individually tweak each sub-material.  In terms of the decals, you would use a Composite Map  (i.e, different than a Composite Material) to achieve the overlay of the decal with a an opacity mask in the mask slot of the decal layer to just show the decal itself.   

I hope this is clear and helps you out.   There are certainly other approaches, but I think this is easiest with best control over the results that you want.  

[10DSpace]

Hi @Anonymous 

Personally, I think an easier workflow is to work within a single instance of the Unwrap UVW modifier on your car model.  In combination with assigning a multi-subobject material to the car model, you can do what you want to do.  In other words, I would NOT use a composite material as you are trying to do, but instead use a multi-subobject material on the car model.  I don't know what version of max you are using, but I'm pretty sure the feature to assign and select polygon ID's from within the Unwrap UV Editor has been available for some time now.  So if you have already setup all of your polygon ids the way you want, you can select these polygon ids for further UV editing or selectively display the UV's by selecting the ID you want in the dropdown list (see below):

What I'm essentially trying to do is have one material, but have multiple decals at good resolution on that material, with a side benefit of being able to change those decals.

In essence, with the above approach you have a single-Multi-SubObject Material  for your model and you can individually tweak each sub-material.  In terms of the decals, you would use a Composite Map  (i.e, different than a Composite Material) to achieve the overlay of the decal with a an opacity mask in the mask slot of the decal layer to just show the decal itself.   

I hope this is clear and helps you out.   There are certainly other approaches, but I think this is easiest with best control over the results that you want.  

[Anonymous]

That is actually very interesting. Using Multisubobject and MatID's might be one step more concise than what I had in mind. I think I actually may have solved the Map Channel thing, but Mat ID's may serve multi-duty acting as key parts of the mesh, parts of the mesh that need attention, and key places that the next user could look to for map channels, and to aid in selection. And as far as I can tell a composite material doesn't export. I really appreciate your answer. It's helping me think this out.  One reason I would want to use Map Channels though, is that say the car I'm working on has tiny tiny logos, with map channels I could expand their area for higher res. 
I'm still reading further, but do you know what I mean?

[Anonymous]

That is actually very interesting. Using Multisubobject and MatID's might be one step more concise than what I had in mind. I think I actually may have solved the Map Channel thing, but Mat ID's may serve multi-duty acting as key parts of the mesh, parts of the mesh that need attention, and key places that the next user could look to for map channels, and to aid in selection. And as far as I can tell a composite material doesn't export. I really appreciate your answer. It's helping me think this out.  One reason I would want to use Map Channels though, is that say the car I'm working on has tiny tiny logos, with map channels I could expand their area for higher res. 
I'm still reading further, but do you know what I mean?

[10DSpace · Accepted solution]

One reason I would want to use Map Channels though, is that say the car I'm working on has tiny tiny logos, with map channels I could expand their area for higher res. 

The fancy term for what you are referring to here is Texel density, or the amount of space in the UV map tile that is devoted to your logo.   But if you use a single Unwrap UV modifier, you do not need map channels to accomplish the UV map layout for any material ID you are working on.  Within the Unwrap UVW Modifier, you just display and select only the polygon id you want and  scale the relevant UVs as you want.   Then display and select the next material ID and work on that.... etc.  So this is not a reason to reject a multi-subobject material workflow that I have suggested.   

And as far as I can tell a composite material doesn't export.

Since you mentioned export....Although the above workflow works fine within Max, be aware that if you export your mesh for use in another application, you will have to learn about another important concept, which is Multiple UV tiles.   This is because the UVs you have currently set up for your multiple maps are no doubt overlapping in the same UV tile (U1V1).  You can see this when All ids are selected in the UVEditor display dropdown.   Max knows how to keep these separate material IDs separate but other applications do not and your materials may come out with all of the materials composited over each other across the mesh when viewed from within the other application.   So if you plan on exporting,  the solution is to simply move the UV islands for the different material IDs to different UV tiles so there is no overlap of any UV islands.  The image below shows this done for the six sides of a box.

 Since there is now no overlap of the UV islands, the other applications can correctly display the maps assuming they support a multi-UV tile workflow which most do.   A UV multi-tile workflow is pretty common these days so it is worth learning about  if you are not already familiar with it.   

In case you are not familiar, here is a link to a video explaining how to do this in max in preparation for an export Substance Painter.

https://www.youtube.com/watch?v=1BplWdNkmbs

Hope this helps.  

[10DSpace · Accepted solution]

One reason I would want to use Map Channels though, is that say the car I'm working on has tiny tiny logos, with map channels I could expand their area for higher res. 

The fancy term for what you are referring to here is Texel density, or the amount of space in the UV map tile that is devoted to your logo.   But if you use a single Unwrap UV modifier, you do not need map channels to accomplish the UV map layout for any material ID you are working on.  Within the Unwrap UVW Modifier, you just display and select only the polygon id you want and  scale the relevant UVs as you want.   Then display and select the next material ID and work on that.... etc.  So this is not a reason to reject a multi-subobject material workflow that I have suggested.   

And as far as I can tell a composite material doesn't export.

Since you mentioned export....Although the above workflow works fine within Max, be aware that if you export your mesh for use in another application, you will have to learn about another important concept, which is Multiple UV tiles.   This is because the UVs you have currently set up for your multiple maps are no doubt overlapping in the same UV tile (U1V1).  You can see this when All ids are selected in the UVEditor display dropdown.   Max knows how to keep these separate material IDs separate but other applications do not and your materials may come out with all of the materials composited over each other across the mesh when viewed from within the other application.   So if you plan on exporting,  the solution is to simply move the UV islands for the different material IDs to different UV tiles so there is no overlap of any UV islands.  The image below shows this done for the six sides of a box.

 Since there is now no overlap of the UV islands, the other applications can correctly display the maps assuming they support a multi-UV tile workflow which most do.   A UV multi-tile workflow is pretty common these days so it is worth learning about  if you are not already familiar with it.   

In case you are not familiar, here is a link to a video explaining how to do this in max in preparation for an export Substance Painter.

https://www.youtube.com/watch?v=1BplWdNkmbs

Hope this helps.  

[Anonymous]

Sorry for one last question.  What is the method to get them to pack all the same scale but along multiple islands?  I suppose I could pack them into one and scale them all up.

[Anonymous]

Sorry for one last question.  What is the method to get them to pack all the same scale but along multiple islands?  I suppose I could pack them into one and scale them all up.

[Anonymous]

Oh darn, sorry, it seems I didn't post my thanks.  earlier.   Thank you.  And thanks for keeping it on track.  My pets were like a zoo yesterday and I didn't feel I could word things right.

I can see with my method, I am going to have to bake the textures and overlapping UV's and lots of other problems.  It sounds good now, but I'll probably have to rewind.

[Anonymous]

Oh darn, sorry, it seems I didn't post my thanks.  earlier.   Thank you.  And thanks for keeping it on track.  My pets were like a zoo yesterday and I didn't feel I could word things right.

I can see with my method, I am going to have to bake the textures and overlapping UV's and lots of other problems.  It sounds good now, but I'll probably have to rewind.

[10DSpace]

OK, glad I could help.

[10DSpace]

OK, glad I could help.

[Anonymous]

Okay a deeper thanks.  I looked deeper into what I was trying to do, and you were doubly correct, and I'm adjusting my workflow plan.  Composite Material and Map really are for Max purposes.   So I literally am back to square one... but wiser.

I wanted the convenience of decals and a shorter path to export.  I don't have the means to do an exceptional bake, so Mat ID's and UV work may be the refinement I need.

[Anonymous]

Okay a deeper thanks.  I looked deeper into what I was trying to do, and you were doubly correct, and I'm adjusting my workflow plan.  Composite Material and Map really are for Max purposes.   So I literally am back to square one... but wiser.

I wanted the convenience of decals and a shorter path to export.  I don't have the means to do an exceptional bake, so Mat ID's and UV work may be the refinement I need.