Going crazy with smoothing groups. (3dsmax- HELP!)

ImSlightlyBored

Ive gotten myself a mesh made to import in to xNormal and UE3.
Triangles, all that jazz
but the one thing thats giving me a headache is bloody smoothing groups. Using Max 9, I'm coming up with nothing on how to export smoothing groups. I've never encountered them before, so a little help would be good. I THINK I'm doing what seems logical
(selecting polys, clicking smoothing group = x to assign to them)
but when exporting as .ase or .obj and viewed in either UE3 or xNormal I just get one huge smoothed over crap mess

tried searching this forum for advice and I've googled to no avail - anything out there is either too vague or not geared to games and the like at all


Help! Im at the end of my tether.

Edit: heres a screen of what im doing in max, and what I'm getting in UE3
I actually think this might actually be it and its UE3's slightly plastic rendering skills, but note on the front facing flat plane theres still a bit of curvature hinted at. Is this just inherent to UE3 or am I STILL having problems?


In this case it seems like Im splitting hairs as my output is near enough Ok now but for future reference, I'd still like any advice and tips. Or even just methods.


My incredible lacking smoothing groups skillz


Unreal Engine output (diffuse&emissive only)

warby

i don't know about the max actor X plugin but the maya version has a checkbox called "obey hard edges (convert to smoothing groups)"

if you don't have that id say just split your model in those places for real

EarthQuake

You can manually detach the faces instead of using smoothing groups for a simple fix.

Eric Chadwick

Set all faces to the same single smoothing group, and either split into elements as EarthQuake says, or double the edges (chamfer) where you want the hard shading between smoothing groups. The latter takes a little more time to make, but can give you variable hardness (thinner chamfer = harder edge, wider chamfer = softer edge).

Xenobond

[ QUOTE ]
You can manually detach the faces instead of using smoothing groups for a simple fix.

[/ QUOTE ]

Also you can split edges if you have a part where you want a hard edge, but needs to be smooth with a larger part.

pliang

Depending on where the parts are going to be smoothed...you can cut some edges in between some of the edge loops for that effect as well.

Turbo smooth?

ImSlightlyBored

cheers everyone
I ended up using the detach method and it seems to have worked fine.

Theres still some smoothing issues but I think this is just lack of experience with UE3 - looking at the same model in xNormal is perfect now - that front panel is perfectly flat but with UE3 I'm still getting that slight curvature. Bugger.

Cheers again

Neox

But doesn't that work against the culling algorithms of U3? I thought a mesh in U3 has to be closed to cull away whats behind that mesh?

jogshy

Try to avoid the max2obj exporter... messes a lot the exported vertex normals sometimes ( specially for cube objects ). Better export as ASE or 3DS.

FAT_CAP

ActorX definately retains smoothing group info from MAX to UE3 automatically.

.ASE export also should preserve smoothing groups between the two programs - have you got the MESH NORMALS option checked in the.ASE export?

Ruz

SEKNeox - you donpt have to have everyhting closed now. When I first started with unreal engine 3 at a previous company you had to , but it seems you don't now.

realityV

What you are seeing is Vertex shading in the Static mesh viewer on UT3. So the light is drawing a shadow from one corner vertex to another based on your smoothing group trying to shade across to faces that are at an angle greater than roughly 45 degrees.

You should get decent results is you select your entire model either with faces or elements and then doing an auto smooth with the Threshold set to 45 degrees. Then re-import. You can then tweak the smoothing groups as needed.

If I'm not mistaken, Vertex shadows are the only option in the Static mesh viewer. The over-ride would be if you were to create a light map and baked for use in game, but that would be inefficient since you could render your own Ambient Occlusion map and multiply that over the diffuse in the shader.

hope it helps.