It's to do with the sub-div smoothing preview (3 on the keyboard), by default just internal's will smooth but the UV borders will not. If you were to actually smooth the mesh you can decide if you want to also smooth the UV borders. Since the borders don't change then the textures will still apply properly, but the internal UV's of the shell will smooth out.

@@MichaelWildeVFX Ah I see, so it is just a smooth preview? Sry I am a Max user and I don't think Max has a feature like that, you would probably need to apply a turbosmooth modifier to do that there but that would smooth down edges as well

Good question - So the way I do it in Maya, open your UV editor and then the UV toolkit. Under Transform there is a bit called texel density. Select the shell you want to have the scale of, then press Get. On the other shells now when you press Set it will scale them all to the same scale.

@@MichaelWildeVFX thank you so much, that did the trick. You are nothing short of a wizard good sir! I really appreciate your help and time.

Hi Timmy, thanks for the suggestion! I have a few already on Arnold which is used in some studios. Other software I know that is used like Clarisse I don't know well enough to be teaching (/ I hate using it haha). I've recently started using Redshift but I'm by no means qualified to be teaching it yet. If the arnold stuff sounds of interest check it out, but in general for lighting and rendering while it helps to know the one a studio uses I've found that you can often learn that on the job, so it's more important to understand it as a whole and how lighting & rendering settings work, rather than getting hung up on a specific renderer.

@@MichaelWildeVFX Thank you very much for the clarifications.

Substance saves it's strokes in 3d space, so if you move UVs but not the model it may transfer the hand painted stuff okay, you should just try and see how it looks. Chances are you will have to repaint something though, this is why planning ahead with UVs is so important :)

@@MichaelWildeVFX yeah I figured that out, LOL. This was the first time I've ever used substance and UDMIs. When I move the UVs back in Maya, the textures stay put on the grid where substance put them. I was hoping there was some way to make the textures move wherever I move the UVs. But maybe that was just wishful thinking, LOL

Generally texel density stays the same regardless of mesh size or material as you want the same resolution on one section to another. If you have a close camera on something you don't want the metal parts to look low res VS plastic bits on your mesh. So yer, generally you set everything to the same density unless you have something like backside faces that are never seen, or sometimes faces and eyes are given more resolution in a production as they are the first thing you look at

@@MichaelWildeVFX got it! Thank you

Hey yes Substance does have UDIMs now, I have a video about it on my channel: kzfaq.info/get/bejne/ecV3p6-lzLzMXY0.html

It's not perfect but it's one of the main features it was missing! And yes OTGW is bloooooody incredible :D

Make sure you only have one material assigned to your mesh that you are importing

@@MichaelWildeVFX I have to assign only one material like lambert to every model in my scene. then arrange the UV in a Different box-like UDMI. Then we are able to import all scenes in the sustain painter Sir?

So you're right with your first bit - UV's are a way to associate a point on a 3d mesh, to a point on a 2d grid across a (0,0) -> (1,1) grid. That UV point can then pick up the texture lying on the same point. What UDIMs are in essence is extending that (0,0) -> (1,1) grid to a range above 1! While the naming convenions are 1001, 1002 ect. what they actually translate to is co-ordinates on a grid above 1,1. So a UDIM of 1002 is a grid from (1,0 )-> (2,1) I personally don't like thinking about it like that, I find it much more confusing, but if it helps you then that is what is happening. Some software like mudbox actually uses that as the naming convention instead of your standard UDIM naming conventions of 1001 and up. I would personally suggest getting comfortable with the UDIM naming conventions as mainstream texturing and rendering software these days rely on it! All maya or any other software knows is that its UVs sit outside of that (1,1) grid line, but when you tell inputted textures to conform to UDIMs (like I do with Arnold at the end) you are telling it that when an UV falls outside the standard (1,1) grid position, please assign the associated UDIM numbered texture to it.

@@MichaelWildeVFX I had another question. How do you keep the consistency of the udims shell when you use the get and set tool. As it just goes very tiny, and I'm manually trying to scale properly. Unless I am doing something wrong. Thanks!

@@Ange-C So the get and set tool are incredibly powerful. To use it, all you need to do is select a UV shell that you want to get the scale from. Select the UVs of the entire shell then press get, then go to another UV shell and press set to give it the same scale.

@@MichaelWildeVFX hey , thankvyou for that. I had another question about scaling. In the uv when I select a set of uvs like bolts and set it to the same value as the other, they get very tiny. Should I be concerned? Or is that normal. And do I manually have to place them in the udim as one set of group or can layout do it auto for me. Sorry if I don't make sense.

No, that's what a metalness map dictates in the shader

@@MichaelWildeVFX Thanks Michael!

UV sets are used for some things in VFX pipelines, but rigging, grooming or making different LODs are the only times I've used them - not texturing. You can combine UDIMs and UV sets. Ss far as I'm aware, you can't set up shaders to use different textures on different UV sets of a single object so they're pointless if you want any of the benefits of UDIMs like I talked about in the video. Also Mari can't use them I don't think and I'm not sure Substance can either.

@@MichaelWildeVFX Thanks for replying. Actually yeah we use to use UV sets and any number of different textures within a "layered texture" in Maya. Often times the texture on the top would be a decal type thing but we'd use it for dirt and what not as well back in the day. I'm pretty sure we did this on Battlefield 2 expansions. I haven't done much texturing in a long time so i'm trying to get acquainted with newer pipelines. Granted not many people used UVsets back then but I loved them. I can get used to UDIMs but it was kinda nice to have the little drop down to just switch to which UV set you were working on. Again.. I can see the benefit of having them all visible at once as well :D

Hi there, It really does depend. The most important thing is making sure your textures have enough resolution. One of the pros of UDIMs is that you don't need one 16k image, as you can have many smaller 4k ones. So really enough to make sure your textures hold up in your renders. I've had models with just 1 or 2, and I've had models with 100+ because they were so large!

@@MichaelWildeVFX i get that but how to know how many , for exemple i used have a UV cheaker (1024x1024), them i set the camera as close as it gonna be when filming them i start to uv and separete in more UDIMS till i dont see the pixelated of the 1024x1024 cheacker , is that a good workflow or theres a better way . thanks for replying

@@claytomcs I usually set my largest UV island to fit in as well as possible to one UDIM, set the rest to that scale and then just have as many as it takes to fit into that space. 1k is really low these days for textures unless you're doing games which doesn't use udims, so you can always do 2k or 4k textures

@@MichaelWildeVFX ooh i get it now, the 1k texture is just to orient myself about the closes it will ever get to the camera but u really helped me on that matter =) thanks

In Mari? You only need one colour node for all the udims. If you want to add different colours to different parts of a mesh you need to merge stuff together and mask it out. Check out my video on the node graph for more about that.

@@MichaelWildeVFX no no. I was asking in maya. But I got it. You just put one of the textures and maya detects every other texture using naming convention. Thanks for the video. Helped me a bunch

@@Nexist at 12:07 I go through adding UDIMs in Maya, that's the proper way to do it :)

@@MichaelWildeVFX yeah that's what I used. Thanks for your help

Hello! I was wondering the same thing. I found this : www.artstation.com/artwork/W2PdQ2 ;)

^ couldn’t have said it better myself. At the end of the day the main thing with VFX is it needs to hold up to the camera

Yes it does now, I've got a video breaking it down on my channel :)

@@MichaelWildeVFX thanks for the quick response. 🤙🏼Ill watch it right now.

They’re not used in games no

@@MichaelWildeVFX but games get better for example you have 3/4K texture game Assets get split into BG Assets Far Assets and Assets that are damn close lets say we want to have a high texel density in 1 Object that is always seen. For example weapon in Ego Shooter and you want realy nice textures no chance for UDIMs?

I’m not a games artist so I don’t know but I know they don’t currently use UDIMs

@@rephayersecondchannel you'd use tiling textures and multi layered materials setup