Guna's Polybook

Only three lessons in Chapter 1 left — the face, the stove, and cleanup. I am close to completing the modeling part! He has so many details now that it is hard to capture the progress clearly, but I tried my best.

Just a little over 3.5 months, and the modeling of the Pothead is complete! Since I work full time, most of the learning and modeling happened during evenings and weekends. He still resembles the original, but with enough changes to feel like his sibling—let's say, the brother of the original Pothead.

At one point in X-ray view, he looked like a duck. I wanted to post this blooper here. :)

Even though it’ll be hard to see the details inside his head, I still wanted to model it the way I had envisioned it, including a more detailed lightbulb.

I honestly don’t remember if I’d ever done UV unwrapping before. Fingers crossed it goes well!

Sometimes, especially when I’m tired, the path I’ve chosen starts to blur and doubt creeps in, your support and encouragement helps me to keep going. Thank you!

Chapter 2 complete—almost!

I’ve UV unwrapped and assigned materials. I used Average Island Scale and packed everything using Blender 4.2’s default packer, which actually seems to work beautifully. This is my first time packing UV islands, so I’m not sure if the result is considered good—I haven’t done this in earlier versions of Blender.



Now I have a question:

How do you decide which objects or parts of the model need more texture resolution?

What’s your approach or strategy when allocating UV space to different areas of the model?

I'm working on Pothead and trying to get better texel density. One UV map didn’t feel sufficient, so I created two UV maps and split the islands between them. I’m using the same materials across both UV maps, but I have two base colour images—one for each UV map.

My question is: how can I set this up in Blender 4.2 so that each image uses its corresponding UV map, and I can see both textures combined correctly in the 3D Viewport while texture painting?

Hopefully I explained clearly what I’m trying to achieve.

Thank you for your time, Martin. I may not have explained myself clearly, or I might not fully understand how to implement the solution you suggested.
I’ll do my best to explain the issue once more so we’re on the same page.

As an example, the pot is on the main UV map, and the legs holding the pot are on the secondary UV map. On their respective maps, both objects occupy similar UV space, but each uses its own UV map. Both objects share the same material — Cast Iron.

I assumed that having two base color textures (one per UV map) would work — and maybe it does — but how can I set it up so that in the 3D Viewport, each object displays the correct base color from its assigned UV map, both at the same time, without overlapping or interfering?

Is there a way to preview both base colors correctly — one per UV map — on their respective objects in the same 3D Viewport during texture painting?

I always try to find solutions when I do something differently from the course, but this time I’m stuck. No matter how deeply I dig, I can’t seem to find what I’m looking for — or maybe I don’t fully understand what it is I need.
I’m sorry about that, but I really want to complete this project.
I want to find a solution and see it through with two UV maps. Honestly, I don’t want to go back to using just one — even though that would make things much easier, putting me back on the beaten path, guided step by step, instead of wading through the swamp I currently feel lost in.

The UDIM nightmare returns, hey spikeyxxx ?

So I just spent ages writing out a really long (and hopefully good) response, but it seems the CGC servers thought I was a bot and deleted it - rip.

I'll jump into my computer tomorrow (actually today because I'm up late watching tv oops) and tell you everything I learnt about UDIM's and Texel density and why they are good and why you should use them.

And also about when I got roasted by Martin and dostovel for not playing with my UV tiles correctly lmao. 

Hey Guna!

First off, well done for getting this far into the Pothead course. It is absolutely not an easy one, nor is it for beginners. Not that you are, evidently so as you have made it this far. I've read through this whole thread, you're definitely not a beginner anymore - everything is looking impressive and rad as hell.

Second off, well done for getting this far into the Pothead course. It's a wild ride, but not without pain and suffering.

Speaking of, Hi my name is Harris and I love pain and suffering - spikeyxxx and dostovel can back me up on this.

To answer your question, yes, you can probably use multiple UV maps and connect them in the shader editor like Spikey mentioned. I can't remember how to do that exactly, but I belive you can assign them somewhere in the properties tab.

However, I'd highly recommend using UDIMs, or at least learn about them, especially if you want to precisely control your resolution across the board.

What are UDIMs, why are they fun, and why should you use them? Also what is Texel Density, and why should you care about it more than if you are wearing matching socks... and what does UDIM stand for? For the latter, I don't know, but some people call it the United Dairy Industry of Michigan

For UDIMs, and this is an unoffical description, as I am running off the top of my memory, but it allows you to separate your models into multiple UV tiles with different resolution sizes, all while keeping it within one single UV map.

For instance, you could have an 8k tile, a 4k tile, and a 2k tile all within the one map.

These are generally split into different components of your model, ie you'd have different tiles for the head, arms, legs etc. You'd use the higher resoltion tiles for the important model parts that are going to be seen the most, or be seen close up. And you'd use smaller resolution tiles for the less important parts - the bits that are less likely to be seen. Or you can use the same resolution for each of them if you so choose. This will lead you down the path of texel density - more about that later.

For example, you might give Pothead some denim jeans (if he wore them) with an 8k tile, but then you'd make his underpants with a 1k tile (because nobody wants to see those). Or in a better example, you might texture the face and head of a tyrannosaurus with an 8k, or even 16k tile because you're going to zoom your camera right in for some terror defining hi-def close up shots to show the ferocity in its eyes and teeth. But you'd use something lower like a 2k tile for the tail because you might not do as much of a close up shot of it.

By allowing you to use multiple resolution tiles, you're affording yourself the ability to 1, balance things out by taking away unneeded sparkle from unimportant areas and giving it to the more important ones. 2, have control of your file sizes, while also having control over the memory usage of your computer. And 3, the coolest part, you can work across all of them all at the same time!

For instance, I used about 9 tiles for Noodlehead, ranging from 2k up to 8k (I even tried 16k but realised that was crazy and ridiculous) (to be fair, that entire project was crazy and ridiculous).

What about texel density? What is that and why should you care a buttload about it?

Each of your UV islands takes up a certain amount of texel density in your UV maps. The bigger the island, the more resolution it's going to get, and vice versa. Back to the example of pothead's denim jeans, you'd make the UV islands for the main parts of the jeans larger within the map so you can show off the denim material at a higher definition. And you'd make the islands for the something like the thread and stitching much smaller on the map as it doesn't need as much definition (the thread and stitching might be a bad example as there are probably better ways of doing that specifically, but you get my gist).

The packed UV maps you have posted look super clean. My only concern is about the really small islands that I can see. I don't know what model parts they are for, they could be fine, but they could also be too small - unfortunately, this is part of the frustration of packing and why a lot of people hate doing it. The good thing though is that you can select your islands in the UV editor, move your cursor to the 3d viewport, and hit the period key on your numpad to frame selected and it'll show you exactly where on your model it is - this will help you work out if the island is perhaps too small for the size of the geometry. Again, this is contextual, and the island size depends on how much resolution you want to give it, as well as the resolution of the tile itself. If the resolution is too small for what you want, it'll come out pixelated.

All of this then equates to how you pack your islands. I'd suggest looking into an alternative unpacker than the default Blender one. I initially used it and it turned out to be more trouble than warranted - however that might just be me. But I found that averaging the UV islands was the biggest frustration. I believe I used the free packer that JL mentions here. Don't leave things entirely up to the computer tohugh, let it do half the work, and then through with your own judgment and make any changes if need be.

Texel density is really important, especially when working with UDIMs.

I'll say that again, but louder, TEXEL DENSITY IS REALLY REALLY REALLY IMPORTANT, ESPECIALLY WHEN WORKING WITH UDIMS. Because as a first time packer, you might not be aware that you have made some islands too small. And you'll then get far down the line, maybe hours, days, or in my case months and get stumped when one part of your model looks high-def and cool and all textured up, whereas the part right next to it looks like dog barf. This absolutely happened to me. It sucked, and it broke me. I believe I took a round about way, and created a new UDIM tile and just rescaled the island over there while unfortunately having to repaint it - which is a very unoptimal way of doing things.

Here's a few links to info on texel density and UDIMs. Aswell as one of Chunck's videos where he covers TD in his video game asset course that I found incredibly helpful.

https://www.reddit.com/r/blenderhelp/comments/sn0u4i/can_someone_explain_texle_density_and_udims_to_me/#:~:text=Texel%20density%20is%20the%20%22concentration,let's%20round%20to%204000x4000%20pixels).

https://www.reddit.com/r/Maya/comments/x97vk8/4k_texel_density_help/
Even though this is to do with Maya, the concepts still matter, big time.

https://www.youtube.com/watch?v=LR3Y9R2wmdI&ab_channel=CGCookie
JL explains how to set UDIMs up and use them - I'm not sure if this has changed in the updates since though.

https://www.youtube.com/watch?v=55sGQLX7iho&t=681s&ab_channel=CGBoost

https://cgcookie.com/lessons/understanding-texel-density
In this video Chunck uses the texel density checker addon - I used it, it's great. But I can't remember how it works. Check it out though after watching the video

Unrelated, but for the love of god, make sure you don't leave orphaned faces without material mothers.

So to go back to your question, use UDIMs if you want more control over the resolution all across your model while also being able to work across multiple maps at the same time. But remember to remember about TD.

And lastly, Pothead is a mighty course. Don't feel like you're not doing it right, or that you're doing something wrong just because it's taking a long time. Or that something has gone wrong and you can't work it out. This course tests you on that, and the best way to learn how to fix a problem is to make it in the first place.

Martin and Omar will be here for you if you need help. You could even summon Dwayne to come in. Hell, even tag me if there's something you think I can do beyond this.

It took me about half a year to get through it as I decided to go down the rabbit hole of making him a companion. This course is a culmination of many topics and you should continue to take your time to learn about everything covered in it, while also taking the time to make this pothead into your pothead!

I'll keep my eyes open for when you finish it!

Another quick note, I belive JL mentions it in the YT video I added, but you can set the UDIM tiles to repeat if I remember correctly. So you can have your same base colour repeated across multiple tiles

Hi Harris Yeehawcowboyletsgo,

And yes, Martin spikeyxxx and Omar dostovel have been incredibly helpful and supportive since day one, all the way back to my first post in this poly-book.

Texture painting was a lot of fun, albeit not with without it's frustrations. I'll link you to a problem I was having.

A quick bit of advice with texture painting though would be to watch all of chapter 3 before doing it. In the link above, I was stumped on a texture seam. However it gets resolved in a later video in the chapter. From memory, the solution required a bit of hand painting with the bump layer to help blend the seam.

But again, tag me here if you run into problems and I'll try and help!