What am I doing wrong? Low poly/baking monstrosity

karmiclychee · Sep 2012

So, I'm teaching myself as I go and I've reached a point where I need to troubleshoot my lowpoly/texture-fu. I understand the concept and the how-to, but the finer nuances seem to elude me. Here's what I got:

The problem - rendered, hideous (Marmoset):

Original High Poly:

Low Poly:

Low Poly with wire:

I don't even know what the right questions to ask are, so have at!

JamesWild · Sep 2012

Are you baking with Max? You need to be careful with the cage to prevent distortions like that. Instead of just pushing, select the cage verts and scale them so the cage barely moves along the axis it's distorting on but has plenty of space on the axes it's not.

karmiclychee · Sep 2012

Sorry, should have mentioned - Modeling in Max and baking in Topogun - extending the cage by about 9 units to cover the high poly.

I don't quite follow you though - "barely moves along the axis it's distorting?" I think I know what you're getting at, maybe, but I'm not sure.

cw · Sep 2012

read this thread chap:

http://www.polycount.com/forum/showthread.php?t=81154

karmiclychee · Sep 2012

Yes. That. I will read that thread. Thank you.

Quack! · Sep 2012

I would remove all of the rivets you have modeled and let them be described by your normal map. You have to let your normal map do the talking. Also remove those TINY edgeloops that are very close together. The normal map will describe that area. After you have removed all of those, convert your saved tris into more sides for your base cylinder shape. The more your low poly looks like your high poly, especially on cylinders, the less distorted your bake will look.

Also make sure your normals are the correct orientation, inverted or not. Not sure what orientation topogun uses.

Good luck.

ZacD · Sep 2012

First problem is the low poly has a lot of extra geometry, remove anything that isn't helping the silhouette, also you could user more divisions on the sides of the cylinder, you got about 20 sides, 40 wouldn't be much if you got ride of all the extra loops.

karmiclychee · Sep 2012

Thanks so much for the advice, guys. I've been noodling all day and came up with the following. I went ahead and modeled the rivets right in since I didn't like how pasted on they looked when I tried to rely entirely on the normal. They're significant enough that they effect the silhouette, I think. Killed a bunch of the superfluous geometry, but I think I was to scant on some areas and too detailed on others (like rivets, for instance).

cptSwing · Sep 2012

I think James Wild is referring to this process, ie editing your cage to get rid of the waviness (snagged from Ben Mathis' portfolio site). Editing the cage is a bit of a pain unfortunately - but a better option than painting it out in PS, in my opinion.

karmiclychee · Sep 2012

That's what I figured - and yeah, editing the cage is a hell of a lot easier and more precise than messing with PS later.

pior · Sep 2012

Hi there - simply try this :

I used hard edges for presentation purposes but I would recommend you to to smooth everything. There are more to this than meets the eye but for now let's stick to simple things

)

You also need to understand the way the rays are actually being cast during the baking process as this can greatly affect your results especially on a mechanical shape with surface direction changes superior to 90 degrees, like on the back side of your front piece. This is why the 3DSMax cage is such a powerful tool. Have a read there :

http://wiki.polycount.com/NormalMap

As strange as it may seem you also have to consider your lowpoly budget when working on your high, and adjust the way your build your source shapes accordingly. This is an odd mental exercise at first but it becomes second nature with time.

Good luck!

karmiclychee · Sep 2012

It makes sense to consider the low poly when making your highs, of course. It's all part of the process. When I tried similiar to the example you came up with there, the rivets looked like crap - basically weird decals with funny shine on them. I think that they'e large enough to count as part of the silhouette, but that's my inexperienced judgement.

I don't know about the way I modeled the rivets into the low poly - excessive?

Edit: OMG and dat link - everything about everything. My face:

1282786204310.jpg?1318992465

WarrenM · Sep 2012

It depends on how close the player will get to it. If this is something that will be in their face then, yeah, modeling the rivets makes sense. If it's something that will be on the ground and they can't really get up close then letting the normal map sell it makes more sense.

EarthQuake · Sep 2012

The big thing here is you're simply approaching it the wrong way. You're modeling in all the subtle little details that the normal can easily represent, small groves, rivets, etc but leaving the silhouette, which the normal map can't help, very rough. More or less what Pior's image shows.

Compounding matters with your last post is that you've modeled all of the little details directly into the mesh and you're not using any hard edges/smoothing groups, so you're adding in smoothing errors on top of not having the correct sort of geometry to support the end result you want.

You also need to think about scale and how close the player will get to the object when deciding the detail level. (See Warren's post above)

Also, you've got some strange choices in your highpoly modeling. You seem to be placing detail areas in parts of the mesh that will be nearly impossible to be seen in any game. Detail the areas that will be visible, not little grooves that you can't see for all but very specific angles.

karmiclychee · Sep 2012

Thank you guys, for all your advice and consideration. It took me a few days to digest all the bits and pieces, but I managed to get this far on my project. I keep going back to fiddle with the UVs and low polys. The colors are just a really quick first pass to differentiate things, so... yeah.

(Marmoset, of course... because I haven't figured out Unity yet)

What am I doing wrong? Low poly/baking monstrosity

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