Texture control using UV modifier on sub object materials

[Anonymous]

Could someone confirm something for me please.

I can only apply texture controls (using UV modifier) to a sub object material if I first detach each sub object to a separate element or to a separate object. Is this correct? Is there any way around this? I ask because I want to use multi sub object materials put this constraint is a bummer

[Steve_Curley]

Not at all. You need to read up on the Multi SubObject Material, Material IDs and Map Channels. Also on passing Polygon selections up the stack to a UVWMap Modifier.
Basically, for each of the Materials you need to apply, you need to select the associated polys and give them a Material ID, so those for the 1st Material (in the MSO) get ID 1, the second have ID 2 and so on.
If you're using Bitmaps then you will likely need them on different Map Channels - follow the same numbering systam as above.
Apply the MSO to the object, select all the ID 1 Polys then with them still selected add a UVWMap Modifier set to Map Channel 1. Adjust as necessary then collapse the stack.
Repeat for Polys with ID 2 remembering to set any Bitmaps to Map channel 2 and the UVWMap to Map Channel 2. Repeat for the rest of the polys/sub materials.

[Anonymous]

I get that bit. I was focused on the key points. I have been doing as you suggested but hasn't been working for me beyond the the first selection and uv map modifier. I can adjust the tiling etc. Any subsequent edit poly modifiers and uv map modifiers pairs above this in the stack are not working as expected. I make sure the map channel match the material ids but the tiling and other uv map parameters don't reflect the results I get when I test render. You mention collapsing the stack. Is that critical to it working?

Sent from my iPad

[Steve_Curley]

Yes, because if you change the Poly selection at the bottom of the stack you are changing what the 1st UVWMap is using. The only alternative is to add a Poly Select modifier followed by the UVWMap. However, I've had Max crash on me if you have too many in the sequence (previous versions, not tried it in 2015 as yet). The stack would look like:-
UVWMap
Poly Select
UVWMap
Poly Select
UVWMap
Editable Poly
Collapsing the stack each time you change the polys and add the UVWMap prevents any problems and "bakes in" the mapping. If you need to adjust one of them later, just repeat the process of Selecting by ID > UVWmap > Collapse (remembering to change the ID, Map Channel Number and UVWMap Channel Number as appropriate).

[Anonymous]

So the worst that can happen by baking in the texture and you make a mistake is you need to delete texture and start over again?

Sent from my iPhone

[Steve_Curley · Accepted solution]

No, you don't need to delete anything, just select the polys (by ID) and add a new UVWMap (on the correct Map Channel) then make your adjustments. You could also use an UnwrapUVW but for planar faces the UVWMap is easier.

[Anonymous · Accepted solution]

Thanks for your help Steve. Your help is greatly appreciated

[Steve_Curley]

You're welcome 🙂

[ekahennequet]

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