Hard edge normals

Just bevel those edges. Your low poly has to reflect your high poly in shape as much as possible, so try and round off the edges as much as it is in the high poly, without being so... high poly. The low poly cube you have at the minute has some very hard edges and there's no way that your normal map will be able to hide that.

1) make sure to set one smoothing group on whole model

2) edit normals where you've chamfered the edges

3) it looks like known "udk seam problem" - check polycount:

http://www.polycount.com/forum/showthread.php?t=77539

Quote from PogoP

Just bevel those edges. Your low poly has to reflect your high poly in shape as much as possible, so try and round off the edges as much as it is in the high poly, without being so... high poly. The low poly cube you have at the minute has some very hard edges and there's no way that your normal map will be able to hide that.

I don't think that beveling the edges is really necessary for something like this. I just did a quick test bake in max of the same thing using a xoliul shader to render in the viewport:

[Blocked Image: http://i.imgur.com/x1q6P.jpg]

You can try beveling them though and see if you get a better result but honestly, it looks like the green channel is flipped. I know you said you flipped it already but maybe that wasn't necessary?

I'm not familiar enough with xnormal to help but you're going to need to read up with how it works in relation to UDK.

Quote from seir

1) make sure to set one smoothing group on whole model

If he has 90 degree edges (assuming you're talking about the lp) and bakes with 1 smoothing group, he'll get similar results to the UDK shot.

EDIT: Here's the same cube with 1 smooth group:

[Blocked Image: http://i.imgur.com/Q16te.jpg]

you need to rebake the normalmap after you put everything in the same smoothing group!

set all edges to soft edges.

Quote from knj

bunglo can you post screen of that lp cube, only shaded without normal map ? (the one that is ok)

It's just a cube with 3 smoothing groups applied to it (so all hard edges, think that's what they're called in maya) and a flatten mapping operation on the UVs (none of the UVs are stitched together.)

[Blocked Image: http://i.imgur.com/gHEMB.jpg]

Quote from e-freak

you need to rebake the normalmap after you put everything in the same smoothing group!

lol I did rebake it We all know that non-synced bakers don't work well with 1 smoothing group on them sharp angles.

Knj, you're best bet would be to look up baking tips with xnormal for udk. I don't use xnormal or maya but there's no program that has a synced baker with UDK (so far as I know anyway) and there's various things that need to be kept in mind when creating an asset for udk.

Here's the same cube and bake in UDK:

[Blocked Image: http://i.imgur.com/Q2dT8.jpg]

I didn't do anything else, default .ase export settings, didn't flip the green channel of the normal, tc_normamap compression settings on import, compression no alpha on import.

Here;'s the material setup to, as basic as it gets:

[Blocked Image: http://i.imgur.com/E6gVZ.jpg]

knj new post:

Yeah, normals look fine, have you tried re-flipping the green channel yet?

Quote from PogoP

Just bevel those edges. Your low poly has to reflect your high poly in shape as much as possible, so try and round off the edges as much as it is in the high poly, without being so... high poly. The low poly cube you have at the minute has some very hard edges and there's no way that your normal map will be able to hide that.

I disagree with that. It's perfectly possible to do this without bevels on such a simple cube. Would be different if the hp was way more rounded around the edges.

Quote from Steppenwolf

I disagree with that. It's perfectly possible to do this without bevels on such a simple cube. Would be different if the hp was way more rounded around the edges.

Yep. I agree with you Steppen. Pogo: IMO the the shape is just ONE of the things the lowpoly should reflect, what is even more important is the shading of your lowpoly. But it seems like most people don't care about that at all.

I made a quick pic of showing what I mean:

[Blocked Image: http://philipk.net/other/shading.jpg]

The two boxes on the left will allow you to bake out/paint/nDo out a quick flat AND reusable normal map that could be used for tons of different parts on the same model. The last one is something that seems to be common practice in 3D schools and such. There are many things about this one I find very strange:

- This is the one where the lowpoly reflects the highpoly the LEAST.

- An object that is supposed to be flat is instead round..

- Your normal map has to be concave to counteract this convex shading in your lowpoly, and you'll end up with a lot of unique concave shades of various kinds that can only work with this particular object, with this particular shading.

- Your object may look somewhat correct until you want to light it really harshly with strong angular lights and the convex shading of your lowpoly will get too prominent for the normalmap to hide.

- It will get close to impossible to LOD your object properly (why do we see so much LOD popping in games )

With all that said, I think this totally works better for more organic stuff: plants, rocks etc. But I've never understood it for hard surfaced objects.

And yes I know keeping things hard edged and splitting UVs will create more vertex data, but I find a mix of that and tweaked beveled normals allows me to reuse my textures a TON more, and texture memory is still where you're most likely to hit the wall first anyway.

can you show a picture of the middle cube's normals? the explanation and detail is pretty awesome

Yeah whoever said that the lowpoly should always be in a single smoothgroup should be banished from the games industry

Quote from e-freak

can you show a picture of the middle cube's normals? the explanation and detail is pretty awesome

Well, since you have the bevel and shading correct already in the lowpoly any normal information to actually get smooth edges is not necessary when you do that

Or did you want me to show how to actually edit your normals to do that? (basically you bevel your object just like you would with the example on the right and keep everything smooth, but now select all the surfaces you want to be flat and simply point those face normals straight out in the face normal's direction)