Why do you need to use straight uvs with hardsurface models
polycounter lvl 7
Hey I've heard that you need to use straight uvs with hard surface models I was wondering why? Also do all edge need to be straight or only the borders?
Replies
Even if you have straight lines, there's no guarantee that the edge will be falling directly between two rows of pixels. And even so, it would only be visible both when the texture is extremely low resolution, and the camera is very close, which precludes the effect from mipmaps.
All these shells could be perfectly straight, not only will it avoid jaggies.. it will also make it much easier to reuse textures if you want to map part of the texture to another model. All it takes is planning and some extra effort in unwrapping. (using the trick with unitize to unwrap strips; the align tools)
Minor distortion doesn't really matter if you instead end up with nice rectangular shells. Packing them will be a lot easier.
I decided to put seam A over there because it's facing to the back I feel like it's the best place or should it still be on the side?
I made the whole island one thing I don't know what i was thinking to keep it all separate haha
I also merged a lot of separate pieces I didn't think about the waste of uvs if I kept them separate.
I ignored to the whole box uv thing, and kept my uvs as close to the form of the mesh you said. Also deleted some edge loops the smaller chamfers i had them because I thought I needed them for my normal map bake. Deleted some loops on the studs, 5582 Tris in total.
I kept space between the islands for edge padding I didn't even know there was a thing like edge padding(I'm still "trying" to learn a lot). Is there a way to know how much space should be between islands? Here is my new unwrap I think it looks better I hope you won't have to Jackie Chan my ass.
Also, I have a bigger texture density on the sword holder(the thing where the sword goes into I don't know what it is called).
Are the things that still could be better? thanks!!
But I am curious what you consider to be unnecessary distortion to be exactly, Perna. Would you straighten the cap of a tube, or unwrap it as a circular shape, as it appears in 3d? I do the former in most cases, particularly if it were some metal with scratching/anisotropic type rings going around it. The saved UV space from easier packing is also a plus. If there was only a very slight taper to a cylinder or cube, would you straighten that, or leave it with very slightly diagonal edges? I know there are a lot of other factors that come into play, texture res, material, final usage and so on, I just mean in generally, because it seems you would advise to almost never depart from the 3d shape to avoid aliasing. Surely there is a point where the increase in distortion from straightening isn't noticeable, but the loss of aliasing is. Or is it more because, since not everything can be straightened, the differences between two areas is more likely to be noticed? I'm not sure that makes much sense because some things themselves will naturally be straight; you wouldn't ruin those for the sake of consistency... Anyway, interested to hear your thoughts.
As always, "it depends", but here's a general guide: http://wiki.polycount.com/wiki/Edge_padding
I'm somewhat skeptical about real-world practicalities of the linear increase for minimal padding values, but I haven't bothered doing much testing in that area myself.
Another point I haven't seen mentioned yet is grouping your UV islands by their material type, so when the texture does mip down like in those examples above, you don't have small isolated islands that will quickly get, if not engulfed, at least encroached upon by its surrounding materials. It's also just easier to work with when texturing; you can zoom in on the one area that contains the one part you're working on and not have to zip all around the document. It's also handy to orient islands in the same direction of they have a highly directional texture — like wood grain. It also saves you from having to copy/rotate things and so on.
what is a 1024x2048 map? I've searched it but one of the first things I found was not to use it and keep in the power of 2 or something like that.
@Bek
I will group my UV islands by material that sounds pretty smart also nice for making id maps. The handle and the holder I've kept rotated in the same direction as my texture will go. For the other I didn't really care since it's just going to be some type of metal or something along those lines.
I will try to keep a consistent detail level in my next assets. For the word seam I agree that I would be better to put it on the side if it was used for game, But since I just want to get a render in marmoset from my character I think it's better this way. I will try to merge more pieces in future assets. My character is also holding on to an axe I have 16 pieces that all could be merged into one piece I'd better fix that fast haha.
I used to model everything in one mesh didn't matter what it was, if it were a tank I'd thought I had to do it in one piece. After that I thought hey I should keep more pieces separate. But now I'm moving on to hopefully the correct way thanks haha.
I'm going to group UV islands by material.
But I'm still really confused about the whole 2:1 unwrap do you or anyone has some good links to that?
Unfortunately new texture software, Quixel and Substance, would make you problems with both non equal texel size and non square textures. It's their huge drawback.
ps. Same with stretched texels and distorted ones. A few distortion in some unimportant parts could give you more space for important ones. Shouldn't be a dogma either. Also texel stretching in specific direction could give you further mip level switching and better look in certain circumstances.
Very often stretched texels size comes just from trying to pack things tighter just to give more resolution for most visually important and noticeable part of an object . i.e to make it look hi res without extra sub material , mat ID .
Gamers often just don't understand compromises that had to be done to make key things looking good and hi res. Thus they sometimes find bizarre things to complain.
@gnoop I'll just sit back and wait for @perna to reply to you, both of you make sense to me.
Still having things in close plain sight most of a time to be higher res is so logical to me I really don't understand why everybody follow same old "equal texels" dogma and having mediocre looking thing as a result .
The problem is Quixel/Substance where it's a pain in the a.. to work on non-square/ non consistent texel size. And we really need it to be addressed.
But for environments the texture resolution is still not that great . Many parts are not reusable actually or reusable only in very similar conditions. Those boxes are often parts of bigger objects . In general, we still use that phased out approaches, those you hardly see on main characters , animated objects. Environments still use a lot of faked things and often constitute so puzzling task you have to do anything you can to squeeze some extra visual quality.
And when you consider inconsistent density look horrid . I see it often as a way to make already horridly looking low res environment to be not that bad in some key parts . Even characters could be a part of low res environment actually . Crowd in a racing game for example.
ps. Regarding weapon. Well , I never saw such optimization . Left vs right at least. Although I am working for a racing game last few years.
What Kio said is right , I often do it same way. But let's see , to make a wall texture 512x2048 I have to work with 2048x2048 file , actually 4096x4096 master file to have crisper hand painted details, and their "work on smaller resolution, then upscale" is not working really. The nature of all that procedural details turns pretty different with upscaling.
Both DDO and NDO support non-square textures by nature of being reliant on Photoshop, which itself supports the same.
Inconsistent texel density isn't a problem that I'm aware of that would affect working with either tool if it's a deliberate choice being made by the artist. As an example, I frequently give lesser-seen areas like dark crevices significantly less texel density than I do for prominent pieces or smaller components that won't show up well if given the same density as larger components.
If you ever had to work on somebody else's seemingly modular pieces though and trying to make new pieces mapping them to existing textures.. you will appreciate it if they have been extra careful with their uvs. Because matching the curvature is not fun.
Now this doesn't apply to props or other things.. but I'd rather have people be extra careful than not care at all. That's how all these arbitrary general rules start out I guess.
Btw. I'm one of these uv puzzle solver guys who like to go all out and make it perfect, so that's part of the reason for it.
In this example he is wasting a lot of uv space though no matter how you want to go about improving that.
First view impression is most important, and nitpicking about slight, sensible texel density differences is just nitpicking. Unless it's glaringly obvious (if fabric pattern size would be mismatched for example), I don't think it matters to the perceived artistic quality of the asset.
Absolutely yes, large density differences look bad, but it's a kinda purist point of view to deny even the minute ones. I don't see how having more density on some small parts, for example shirt buttons would be a bad idea (they'll actually read as buttons not blobs). Furthermore, I think such small technical issues should not be critiqued, but focus should always be on the art direction.
And the difference could be pretty big when it's necessary. One more example: a group of fresh painted posts, accurate clean wooden fence and some poster or sign attached somewhere . Do you want that poster be equally blurry or still readable? The answer is pretty obvious.
Same as with that nicely decorated belt vs shirt and pants . Looks very right and pro. You just shouldn't do too visually prominent and to specific /contrast details in low res parts and nobody would ever notice anything. I would say "equally blurry" would rather seems pretty amateurish to me.
From a nature of a human vision, we focus more on contrast edges , silhouettes, and some distinctive details while do not focus on something plain and evenly painted. So why do not exploit it. It's a kind of thing you are usually taught at an art school. I mean to do a selection , to filter the reality and find key things and miss unimportant. It's a time saver too when you could just fill low res parts with a color and focus on hi res ones.
I'm not sure I follow you here. Could you show me an example of this problem? I use non-square textures occasionally and haven't run into anything like this yet.
I think this is the golden rule.
Like using always a box for background. ( decades ago) Using weird HDR and bloom effects your eye leaking off . Using "cinematic" indigo or sepia color tinting. Don't using specular mask since roughness is all you need , using only true measured albedo values ans so on an on. They just come and pass.