Lobo3433 opened this issue on Oct 13, 2022 · 12 posts
Lobo3433 posted Thu, 13 October 2022 at 10:58 AM Forum Moderator
Ryan King Art who is a very detailed oriented tutorial creator on YouTube has posted a new tutorial on Texture Painting for Beginners in Blender he covers allot of useful information I am sure many of you would like to learn
Lobo3433
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Miss B posted Thu, 13 October 2022 at 11:58 AM
Ohhhh, I'll have to take a look at that. Thanks for the link Lobo.
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Lobo3433 posted Thu, 13 October 2022 at 12:06 PM Forum Moderator
Your welcome Miss BOhhhh, I'll have to take a look at that. Thanks for the link Lobo.
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RedPhantom posted Thu, 13 October 2022 at 12:17 PM Site Admin
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Miss B posted Thu, 13 October 2022 at 5:43 PM
RedPhantom posted at 12:17 PM Thu, 13 October 2022 - #4446555
Thanks. I've been thinking about learning that aspect of blender next. now, if I could just figure out how to update to the 36 hour days so I have time to do it allI know exactly what you mean. NEVER enough hours in the day.
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Lobo3433 posted Thu, 13 October 2022 at 9:35 PM Forum Moderator
So true there seems to be enough hours in the day but at least it is something fun to keep us Busy :smiley:
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Warlock279 posted Mon, 17 October 2022 at 5:31 PM
I didn't watch the whole thing, but, please don't scale one island on your UV layout just to fill space like that. Yes there are times you can mix and match UV scaling, but that is NOT the time.
Also, the margins/padding he's leaving between the islands are concerningly small. You generally want a couple full pixels between islands, to avoid issues with mipmapping and texture bleed from one island to another. If you know your render engine well, and the exact end use of what you're making, you can sometimes have tighter margins, but the safe bet is a little more padding.
I realize he was just touching on those topics quickly, but I feel like it would have been better had he just pointed anyone interested to his UV'ing tutorial [I haven't watched that, but surely it addresses those concerns?] after the smart unwrap rather than throwing out potentially troublesome ideas.
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Lobo3433 posted Mon, 17 October 2022 at 9:24 PM Forum Moderator
Thank you for sharing your knowledge Warlock you make some very good points especially with leaving yourself enough padding between islands and proper UVMapping is also a whole subject on it's own and one can take several different learning paths as everyone does it a bit differently. Again thank you for sharing your poitn of view and information you shared :thumbsup:I didn't watch the whole thing, but, please don't scale one island on your UV layout just to fill space like that. Yes there are times you can mix and match UV scaling, but that is NOT the time.
Also, the margins/padding he's leaving between the islands are concerningly small. You generally want a couple full pixels between islands, to avoid issues with mipmapping and texture bleed from one island to another. If you know your render engine well, and the exact end use of what you're making, you can sometimes have tighter margins, but the safe bet is a little more padding.
I realize he was just touching on those topics quickly, but I feel like it would have been better had he just pointed anyone interested to his UV'ing tutorial [I haven't watched that, but surely it addresses those concerns?] after the smart unwrap rather than throwing out potentially troublesome ideas.
Lobo3433
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Warlock279 posted Tue, 18 October 2022 at 1:43 AM
A couple really quick, really dirty [really ugly] examples of what I mean about mixing scaling and margins/padding issues for anyone interested. I've taken these examples to extremes for demonstration purposes, cause surely no one is going to scale different parts of a contiguous object at a 2:1 ratio on a UV sheet, and if you did want a solid orange object, it'd be silly to use a texture sheet at all, but here are a couple examples none the less.
When you mix scaling you can get incongruities in your textures that make your seams more obvious. For example in the lines you can see where the pixelation jumps from the scaled up half, to the scaled down half. It's less noticeable on larger/softer lines than it is on smaller/sharper lines, but it's really obvious in the texture example. The texture is refined in the top half, but the bottom half turns to a blurry mess, even tho it was painted at the same time using the same brush. Again, larger/less detailed textures won't suffer as badly as smaller textures, but what's the point of using a 4k texture sheet, if you're gonna paint it like a 512²?
So when is it okay to mix scaling? I avoid it as much as possible but sometimes it has its uses. If you have non-contiguous parts of an object, with completely different textures [say wood on one part, and metal on a another] you can probably get away with a little scaling difference [you don't want to get carried away or you can end up with obviously high vs low res textures]. Similarly if you have an object that has one part that is essentially just a solid a color, and another part that is heavily detailed, you can get away with giving considerably more UV space to the detailed part [in fact you can probably get away with scaling that solid color part down to just a few pixels]. Maybe you've got a control a panel that's fairly plain, but has some buttons on it, and those buttons need to have text, you can probably scale them up so you get a better text resolution. Essentially as long as the two islands you're considering scaling to different sizes don't share a common seam/texture/material you can probably get away with a little mixed scaling.
When don't leave adequate margins, or your don't have padding around your UV islands, you'll make your seams more obvious and you run the risk of running into issues especially with mipmapping*. With good margins/padding you can make your seams almost invisible**. If you don't leave a decent margin, or pad your islands you'll get just the faintest of lines, which really isn't too bad, even in a solid orange on purple example, its barely noticeable, and if you're not looking for it, you might not even notice, who's really going to have a giant low-res orange sphere on screen anyway, but along comes mipmapping and suddenly you've got an obvious ring the further your object gets from the camera, but you don't have the problem in the padded island example.
Now, we're talking two things here, margins [the space between the UV islands] and padding [the space your color/texture extends beyond the edges of an individual island] but they go hand in hand. You want the padding, but to have room for padding, you need the margins. If you're texturing for an offline rendering engine, you can [probably] get away with a smaller padding/margin typically as anti-aliasing handles a lot of the same issues as mipmapping was developed to address, so the render engine may not rely on mipmapping as heavily. For real-time render engines you need to be a little more mindful generally, and a little more generous with your padding. As I said in my first post, if you know your engine, and what your uses are, you can be more selective about how you handle margins/padding, but for general purposes leaving a few pixels between islands is a good habit to get into.
Its worth pointing out that we're talking tiny amounts of space, I might leave a 16 pixel margin between islands on a 2048² texture sheet for example, that leaves me enough space for 8 pixels of padding on each island. That might seem like a lot, but once you take into account the odd shape islands you're inevitably dealing with, its usually pretty easy to find that space. We're also talking minuscule gains were you to eschew margins/padding in favor of scaling and start indiscriminately scaling individual islands just to fill a little more space. You might pick up 2-3% more texture space, which isn't worth the trade-off [risk/potential issues] in my book.
Same with indiscriminately scaling islands. You scaled this island up 8% and that island up 3%, and another 5%, but you probably haven't gained much more than 2-3% of actual texture space across all the islands combined. If you did manage to scale up every island individually any appreciable amount, scaling wasn't your issue, you needed to re-packed your UV map, and re-scale it as a whole.
Neither of these are necessarily huge issues, as noted, I used extremes for the examples, but good habits are good habits none the less.
*Mipmapping, I'm sure you've heard of it, but if you're not sure what it is, it's a texture processing function of render engines to avoid texture flickering. Essentially it blurs [technically its scales down] the texture the further the object is from the camera. Most render engines usually have options to adjust mipmapping settings, strength, distance, etc, but those are typically "power user" options, and come with some caveats.
**There are reasons beyond margins/padding/scaling etc that you'll never truly make them invisible, its just the nature of the beast, but that's neither here nor now.
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Lobo3433 posted Tue, 18 October 2022 at 8:45 AM Forum Moderator
Thank you Warlock279 for all the information it is allot of information to digest but truly appreciate you taking the time to share all this information :clap:
Lobo3433
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Miss B posted Tue, 18 October 2022 at 10:27 AM
Thank you! Thank you! I was going to post asking what mipmapping was. I've seen it mentioned before, but had no idea what it referred to. Now I know! :slight_smile:*Mipmapping, I'm sure you've heard of it, but if you're not sure what it is, it's a texture processing function of render engines to avoid texture flickering. Essentially it blurs [technically its scales down] the texture the further the object is from the camera. Most render engines usually have options to adjust mipmapping settings, strength, distance, etc, but those are typically "power user" options, and come with some caveats
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OK . . . Where's my chocolate?
Warlock279 posted Wed, 19 October 2022 at 10:20 AM
Lobo3433 posted at 8:45 AM Tue, 18 October 2022 - #4446914
Miss B posted at 10:27 AM Tue, 18 October 2022 - #4446917Thank you Warlock279 for all the information it is allot of information to digest but truly appreciate you taking the time to share all this information :clap:
Thank you! Thank you! I was going to post asking what mipmapping was. I've seen it mentioned before, but had no idea what it referred to. Now I know! :slight_smile:*Mipmapping, I'm sure you've heard of it, but if you're not sure what it is, it's a texture processing function of render engines to avoid texture flickering. Essentially it blurs [technically its scales down] the texture the further the object is from the camera. Most render engines usually have options to adjust mipmapping settings, strength, distance, etc, but those are typically "power user" options, and come with some caveats
You're welcome! Sometimes I'm almost useful ... sometimes! :)
Core i7 950@3.02GHz | 12GB Corsair Dominator Ram@1600mHz | 2GB Geforce GTX 660
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