Smoothing Group Trouble... Help needed!

[PogoP]

Hey guys!

I've been doing a quick normal map test, but I'm coming across a few issues with shading across smoothing groups. What's the best way to go about smoothing this piece? It has weird smoothing that seems to make it look like there are more triangles on the model than there really are!

I have a high poly model baked onto a low poly. Does the smoothing of the low poly before baking effect the normal map? I tried a few different smoothing groupings on it and tried baking new normal maps, but it looked the same each time.

Cheers fellas.

[Minos]

Hey guys!

I've been doing a quick normal map test, but I'm coming across a few issues with shading across smoothing groups. What's the best way to go about smoothing this piece? It has weird smoothing that seems to make it look like there are more triangles on the model than there really are!

I have a high poly model baked onto a low poly. Does the smoothing of the low poly before baking effect the normal map? I tried a few different smoothing groupings on it and tried baking new normal maps, but it looked the same each time.

Cheers fellas.

Are you using only one smoothing group for your low poly mesh? I see lots of people doing that and I never really understood why since the crappy 1-smoothing group low poly shading gets baked to the normal map as well.

Max's normal map baker is kinda bad too, have you tried using xnormal for this?

Check this out btw, i learned so much from this video:

http://cg.tutsplus.com/tutorials/autode ... n-3ds-max/

[PogoP]

I've used autosmooth and tried it at different thresholds, and it all seems to look crap

I am using Xnormal too. I must be doing something wrong. Any idea what's going on? I could upload the Max file.

[Nysuatro]

You can add a meshsmooth with iteration on 0 en and a collapse.

[PogoP]

What will the meshsmooth do to it? I'm using turbosmooth for the high, will applying it to the low poly with 0 iterations just smooth the faces?

Any more ideas would be really appreciated; smoothing issues are the bane of my existence.

[-HP-]

Wtf Nysuatro?!

Anyway PogoP, yeah, the first bakes are always a fuckign nightmare, you never know what you're doing wrong. Bottom line is, you will never be able to bake a perfect normal map with perfect shading, try to live with the fact. What you can do, is try to minimize the shading errors. There's a few tricks for that.

- Chanfer most of your 90º problematic edges on your LP, and play around with your smoothing groups, try to have as few as possible. (You wont need many due to the chanfers)

- Play with smoothing groups, add a smoothing group change in places where the player will most likely wont notice, like back areas, etc. Remenber tho, each smoothing group transiction will be a very hard edge on your normal map, therefor breaking the smooth shading, therefor avoid placing one in noticable places.

- Use only one smoothing group for the whole LP, and bake a Object Space Normal map. (All the shading will be read from the normal map normals, and not from the polygons normals)

- Don't forget your UV's also pay an important role, each shell UV will be a hard edge on your normal map, that's why you should try and sync the smoothing group hard edges with your UV boundaries.

I'd recomend you practice with a cube. Bake, rebake, rebake, rebake, rebake and rebake! Test with diferent settings!

Make like a dice or whatever. Then chanfer the edges of the LP, mess with the UV's, mess with the smoothing groups, etc. I too jumped to more complex shit when I started and I wish I didn't, it's a lot of head aches.

And yeah, use xnormal, I know it's a bit of a pain having to export the HP and LP to .obj's, but it's much easier not having to mess around with cages!

I don't want to overflow you with info, but when you have some time for some good old reading, here:

Normal Mapping

http://www.bencloward.com/resources_tutorials.shtml

http://www.poopinmymouth.com/tutorial/tutorial.htm

http://www.gameartisans.org/gamecon/tutorials/tut_3.htm

http://www.game-artist.net/forums/4693-post74.html

viewtopic.php?t=6806

http://saschahenrichs.de/midsizedocs/nvidiatut.html

http://www.svartberg.com/tutorials/arti ... lmaps.html

http://wiki.polycount.net/Normal_Map#he ... 1698abbf3f

http://www.poopinmymouth.com/tutorial/n ... flow_2.htm (workflow)

http://boards.polycount.net/showthread.php?t=51088 ( tutorial: fixing mirrored normal map seams )

http://www.dregsld.com/tutorialfiles/normedit.html (Adding more detail to baked NM's)

http://boards.polycount.net/showpost.ph ... stcount=12 (Combine normal maps in photoshop)

http://www.evermotion.org:8080/exclusiv ... L_MAPS.pdf (Normal maps, and bakings *Must read*)

PS. Don't forget to use a viewport shader, Xoliul's 3DS Max Viewport Shader is the one I recomend.

But the 3ps guys recently release a much more powerful one, that will probably help you get rid of most if not ALL of your shading errors, check polycount and http://www.3pointstudios.com/3pointshader_about.shtml

PPS. Mmm... with a second look at your screenshot, I think your normals are flipped. Go to PS, and flip the green channel. (Or if your using Xoliul's shader, flip the normal map) It should fix most of your problems, but there still is some shading errors there'.

[Nysuatro]

Ow yeah, read to topic to fast. Nvm

[PogoP]

Well, object space normal mapping works perfectly and looks great, but they're not used in games, right?

I've really been messing with this and cannot for the life of me, figure it out. Argh. At the moment, the issue seems to be that there are weird shading issues based on the topology of my model, and the normal maps are not looking 'smooth', there are transitions on flat surfaces that should not be there. Take a look at the following:

You can see where the normal map changes based on the topology of the mesh. Hrrm.

[-HP-]

Try chanfering your geometry!

[PogoP]

I'll try it, but that sucks that you have to chamfer everything

[Surfa]

Just make sure the highpoly has no 90 degree angles (these won't bake properly).

[PogoP]

It doesn't, I've used turbo smooth and the edges are smoothed over.

[Bunglo]

Try flipping the triangles on the area that has the odd shading, might have something to do with that.

[PogoP]

I've made a little progress, it's finally baking properly once I chamfered the edges. Ignore the AO artifacts, they're from the more complex high poly.

There's definitely still some shading issues, but I'm getting there