Barrels are hard.

mortalhuman

Who would have thought barrels would be so difficult? Someone Poleaze halp:

These are what I am trying to bake:
http://dl.dropbox.com/u/1483473/images/barrel/barrel2.png

this is one by itself since I know you'll try barrel1.png:
http://dl.dropbox.com/u/1483473/images/barrel/barrel1.png

This is it in-game, and it has waves and bad shading:
http://dl.dropbox.com/u/1483473/images/barrel/barrel3.png

And this is the normal map (xnormal):
http://dl.dropbox.com/u/1483473/images/barrel/RedBarrel_n.png

Bear in mind that I don't consider this anywhere near done or that it should look good, the diffuse is even just "red".

I figured, I should bake bake bake (xnormal btw) along the way and catch problems early, long before I go trying to get anything special out of this model, I figure, I should get its basic generic shape and normals correct as this is all a learning experience for me.

I looked over this thread but I can't seem to apply what is said to my model, it seems I can't anyway, unless I missed something in there or misunderstood something.
http://www.polycount.com/forum/showthread.php?t=81154

Here are wires:
http://dl.dropbox.com/u/1483473/images/barrel/wires.png

Here is the UV template in all the pics above:
http://dl.dropbox.com/u/1483473/images/barrel/UVold.png

Here is a quick idea I did to post about a new UV template for opinions, I figure it is more intelligent, but perhaps there is still a better way someone can mock up? Maybe I am handling the caps wrong (waves in normal map, other probs all around)?
http://dl.dropbox.com/u/1483473/images/barrel/UVnew.png

I have a feeling this asset has a lot of problems, I am ready for scrutiny and criticisms, and thank you for any time afforded to my problem in advance, it means the world to me.

Mark Dygert

Just taking a wild stab in the dark, it looks like you need to invert your green channel in the normal map. From what I understand its a pretty common setting mix up in xNormal?

mortalhuman

I flipped it, and the result was still wrong - I assume that is because the barrel is vertical in the UVold.png? this is it flipped, it wouldn't cause the other problems tho:

http://dl.dropbox.com/u/1483473/images/barrel/flipped.png

EarthQuake

Simplify your mesh, leave out all those ridges and shit, they're barely noticable anyway. -this will help the smoothing errors. Your baker and renderer(game engine) aren't synched up, so any slight errors will be very visible, the angles/mesh normals of your lowpoly are quite extreme, you can tell by just looking at the lowpoly, so this will cause problems. Removing the ridges and simplifying the mesh normals is a good way to help the issue.

Break the top and bottom caps off into a seperate smoothing group - this will also help smoothing errors

Use that extra geometry to add a little more roundness to the barrel - this will help waviness

Also, use the [img]tag, no need to link to images, you can post them directly. [Edit] From a different thread:[/img]

Mark Dygert

Oh weird, you're still getting funky shading around the rings it must be some kind of a funky cage/projection issue. You might be projecting too far above the surface? Any chance of posting obj files so people can tinker.

I agree with EQ that taking the loops out of the ribs and putting more loops to round out the shape to better match the high poly will help. It will probably clear up the funky rib issues by smoothing out the cage.

And I don't think anyone is looking down on you for posting stuff like this, you're learning its helpful how can it hurt? =P

EarthQuake

Mark: you're thinking ray direction, not distance, the cage could be 400% bigger than the low, but its the ray direction that matters, not the distance. Distance is only relevant when its too short and missing details, or too long and clipping into other areas of the mesh.

Distance can matter when you're tweaking the cage in a non-uniform manner, ie: moving the caps further/close without changing the sides, but this only works in max(maybe XN too?), and the end result is that you're editing the vertex normal direction.

Mark Dygert

The distance matters when the angles intersect at some point in the distance which depending on the construction of his low/cage it might be the problem?

But you're right the angle is what matters solve that and they won't intersect. Or keep the distance under the intersection point should solve it also when it can't be avoided, IF that is the problem.

I can't be certain without looking at the files or having better samples posted, but this was the issue I think he was running into. I think the bottom rib would be more ideal than the top?



Taking the ribs out will smooth out the bake, give him a good projection but it won't necessarily help the silhouette hold the shape of the ribs.

No doubt that if he adds more geometry to round out the cylinder like you suggested it will improve just about everything but he should be able to keep some bump in the silhouette to reinforce the shape of the ribs?

EarthQuake

Yeah, the cage distance can be a problem when it collapses in on itself, I dont think that is happening here though, if you look at his flat normal map, the bake looks fine. Generally you'd seem some artifacts in the map. Also the triangle shape on the ridge wouldn't be very likely to collapse in no matter the ray distance.

The problem with the ridges isn't a ray problem, but a smoothing error problem, so he could add a few more edge loops to solve it. But thats adding more geo for not much effect.

I dont really see much with the ridges that is a problem, as far as "waviness", just smoothing errors there. So messing with the normals a bit likely wont fix the issue: That the baker and renderer aren't synced, thus = smoothing errors. Unless you can really soften out the normals or use hard edges.

If he adds a couple "control edges" similar to what you would do when doing sub-d work, his normal will come out a lot cleaner, with no/less smoothing errors. Otherwise its just best to get rid of the geometry causing the smoothing errors.



[Edit] Arrows for illustrative purpose, showing mesh normals, which are important here because of smoothing errors, not cage projection.

EarthQuake

Another image:


As far as smoothing errors: 1, then 2, then 3 would be the best, but if your system isnt properly synced, all will cause smoothing errors.

The easiest and most effectient solution is to simply omit these details, that will rarely take up more than a pixel or two of space ingame.

Mark Dygert

Yea not synced up, which is why I thought it was a simple green channel fix. That needs to be sorted out first and foremost. Not much sense if blazing forward if that can't be sorted out.

Yep, round out the cylinder be mindful of what angle the averaged normals point. I agree adding the control edges would add a bit more geometry but that would be geometry better spent rounding out the cylinder. It depends on what the priority is and if doing both would be fine I'd go for it.

EarthQuake

Also one more note on when too far of a ray distance can be a problem. Particularly on convex shapes like this:


1. Base mesh
2. Cage, may look problematic but it is fine
3. Cage overlapping onto itself, will cause all sorts of problems here in the inset.

mortalhuman

Still kinda confused about this :P

Part of me is thinking to remove all non-silhouette lines from the high poly and just use that in-game at somewhere near 500 faces (by cutting the 36 sides of the high to 18 as well as taking off the extra lines on flat surfaces) and just use the normal map for surface details and making the lid interesting.

This of course doesn't make me wiser, though :P

Need to try and understand the replies and apply it, can't seem to attach OBJ's for those who requested to see some to tinker, here's a zip.

bh.obj is the high, you can guess what bl.obj is :P

http://supermortalhuman.com/barrels.zip

Sean VanGorder

EarthQuake teaches me things I could have swore I already knew.


http://inception.davepedu.com/

mortalhuman

More playing around going on after all of your posts here, it really seems like a cylinder, a simple cylinder, would be fine for whatever I could throw at this shape, those example images of the 4 possibilities compared really make a powerful statement about just how much can be done with normal maps, but also how little geometry is really needed to make dem shapes in low poly.

The thing now is that I personally like being able to get very close to props and other environment features without have the appearance degrade too much. I know that in games this is not always a luxury that can be had, but our engine is Win/Linux based anyway and won't be substantial in art heaviness any time soon - we're not locked to console specs or projected future console specs, so I think it's worth it to push the detail as much as possible, then scale it back after the fact or along the way if need be.

But when you get close to the cylinder, it will become very apparent that it is very low poly, so I am not sure which way to choose - once the object is crunched to few enough pixels, it is proven in the images above, that extra geometry is a waste and barely noticeable, and in fact produces its own artifacts.

So I'm not sure which way to go - only people who love looking at things up close will ever notice this barrel for anything other than an explosive blob of color on the screen, but it's such a good opportunity to make something awesome and not just something that simply serves its purpose.

Maybe I should find out from the programming lead if we can LOD it. It's really just so he can make it explode and get more work done in that aspect of the engine, but it's a common prop none the less and I'd like it look sweet as possible.

Any extra guidance or shared experiences in making the videogame red barrel while I get together some pics of new tries to share more than welcome and greatly appreciated, thanks PC

mortalhuman

I think it looks better, but it could still use work, I can't figure out how to make it look less cartoony though. Came to 1600 ish tris, it can be brought down to the middle options of the 4 above surely:




Norm, Color, Spec - any adjustments anyone would make right off the bat? I consider this texture kinda bad because I want this to look kinda real, or at least, less toony.

bgoodsell

you need more noise or an overlaid photo texture to breakup the consistant color on your diffuse and spec. The amount of plain red you have is what makes it look cartoonish.

mortalhuman

Is that better? I dabbled some different shades of brown and black and gray on it, what would others and yourself do if told "here is this barrel, improve it" - I think the red spec is probably bad, too. Kinda makes it seem like a special paint.

bgoodsell

do you have a photo reference while your painting your texture? Grab a picture of a barrel that inspires you and look at the ware details on it. This will help you get a better texture.

tristamus

I understand you want a red barrel to get across the fact it's explosive, but my god, that is REALLY FREAKING RED, and perhaps that also is contributing to the cartoonishness.

System

Your diffuse colour map doesn't have enough variation and that's why the specular map derived from it doesn't make much difference. Work from features as a point of reference, for instance the ribs around the barrel could have highlights on them and above and underneath the ribs could have rust or dirt. Same with the top and bottom of the barrel.

Here's a map for an oil barrel I made a while ago as an example.
http://s647.photobucket.com/albums/uu196/GCMax/?action=view&current=Oilbarreldiffuse.jpg

mortalhuman

Spent some time going back and forth with you guys' advices, thanks again! Figured I would come and post to let you guys who cared enough to help out see how it went! Here it is now, I am considering this "final" unless someone here has some extra advice/tips for polish, would love to hear it:

less than 500 tris, 512x512 diffuse and spec, 256 normal cause I could get away with it:

BARDLER

I think you need to pick a style and stick to it.

Either go full on shinny new barrel


Or go worn out, rusty, dented barrel


I think it really depends on your setting on what style to pick. Post apocalyptic settings would have the worn out barrel. On the other hand if you have a modern day game and your level takes place in a oil refinery then the clean new barrels would fit. Or a third option if you have a jungle type map then the barrels my be newer but have mud and dirt built up from the scene.

Bad Spleen

You should do an ambient occlusion bake. If you aren't sure how to do it then pm me, or you can look it up on the internets.

The specular channel shouldn't be red, as I assume you are going for red paint, which is a dielectric material. Essentially meaning that the specular should be white. If it were a bare metal (conductor material) then the specular would be affected by the colour, such as gold or copper.

You need the damage to reflect what the object is made of. The paint would be worn away in damaged areas, exposing the material underneath. At the moment the entire object is shades of red, try making some more harsh paint chips, where the bare metal is visible.

Let the specular map do more for you. You can add a lot of scratching and tarnishing to the specular channel, that doesn't need to be reflected in the diffuse, this will make the surface more interesting.

Make the flammable logo far bigger, it is meant to be a warning, not a cool little sticker.

Anything else, just ask

mdeforge

I second what Spleen said about the sticker. I hadn't noticed it until he mentioned it. I mean, gamers usually understand that barrels (especially red ones) are meant to go kaboom, but I still wouldn't assume it. Plus, it would enhance the result anyway. At least make it brighter. Maybe it is and it's just because every instance of it seems to be in the shadow in your image, I don't know.

I feel the overall specularity is too low. My first impression was "dull."