Help with surface of model.

[xaysana 13]

Hey guys, was wondering what causes this when I import them into O2 via 3ds max. The model is exported as an obj. file from 3ds max. Thanks!

[warlord554 2065]

Its hard to see on my mobile. But O2 has always hated .obj......I apply modifiers and export as .fbx. it holds perfect scale, and flat/smooth edges and faces.

You can try to make those polys flat or smooth manually in O2, or recalculate normals, or tweak your .obj export options. You try a 3ds export/import?

Ive gotten so many problems with .obj i dont even bake with them anymore

Keep us posted :)

[LCpl Aaron 11]

make sure every face has 4 or fewer sides, OB goes nuts at the sight of an Ngon and attempts to make it a quad or tri. or wont import it at all. also make sure your not triangulating when you export as obj, if you want it triangulated do it manually, the exporter may not triangulate in a shader friendly way.

[eyssix 10]

What Sw4l said, having clean topology is required for oxygen. if there is an extra vert in there or and extra edge, youll get results like that.

[Jackal326 1182]

As well as the above suggestions, I would recommend also sharpening the edges of any cut-ins or steep geometry changes within the model. The affected areas appear to be holes or cut-aways within the fore-grip, so selecting the outer edges of the holes and pressing 'U' to sharpen them, will (or at least should) fix the lighting issue you're experiencing.

[x3kj 1247]

doesnt sharpen automatically remove all smoothing groups? thats bad, because if you take a perfectly flat plane with multiple faces on it, and the smoothing groups get deleted, it will be split up too - that would mean you have more vertices then necessary

[da12thMonkey 1943]

"Smoothing groups" is just another method of applying smoothness and sharpness along edges. If a face has the same group number as the adjacent face then a smooth edge is rendered between the two by averaging the vertexes to a single normal. However where there's a boundary between different smoothing groups, the verts that form that boundary are assigned two vertex normals and a sharp edge is formed. i.e. it's the same as a sharp edge in O2 and any other 3D modelling software.

In fact Maya, Autodesk's other main 3D modelling application, uses smooth/sharp edges like O2 in place of the smoothing groups system that 3DS Max has. But it's more flexible than O2 since you can directly select edges in Maya rather than having to be careful about vertex selection picking up an edge that you don't want to sharpen - which happens quite a lot in O2 when you're trying to manually define smoothing groups.

So manually applying smooth and sharp edges between verts in O2 like Jackal describes, shouldn't really result in too much of a difference from the smoothing groups in Max - it's just tedious to do.

As others have stated, the main thing that will bugger up your normals/smoothing groups outputs from other 3D software is if the exporter decides to turn an edge inside a quad, or O2 does it during import - which is why one should triangulate the mesh before exporting it.

Edited March 16, 2015 by da12thMonkey

[PuFu 4600]

"Smoothing groups" is just another method of applying smoothness and sharpness along edges. If a face has the same group number as the adjacent face then a smooth edge is rendered between the two by averaging the vertexes to a single normal. However where there's a boundary between different smoothing groups, the verts that form that boundary are assigned two vertex normals and a sharp edge is formed. i.e. it's the same as a sharp edge in O2 and any other 3D modelling software.

In fact Maya, Autodesk's other main 3D modelling application, uses smooth/sharp edges like O2 in place of the smoothing groups system that 3DS Max has. But it's more flexible than O2 since you can directly select edges in Maya rather than having to be careful about vertex selection picking up an edge that you don't want to sharpen - which happens quite a lot in O2 when you're trying to manually define smoothing groups.

So manually applying smooth and sharp edges between verts in O2 like Jackal describes, shouldn't really result in too much of a difference from the smoothing groups in Max - it's just tedious to do.

As others have stated, the main thing that will bugger up your normals/smoothing groups outputs from other 3D software is if the exporter decides to turn an edge inside a quad, or O2 does it during import - which is why one should triangulate the mesh before exporting it.

To add on what monkey said, DX only uses smooth or hard and EDGEs, while other software (like 3ds max) uses smooth groups for faces. Somehow, as i have used both software, i find max approach better for viz and vfx, but less so for the games.

[xaysana 13]

It works! Thanks everyone for your kind advice :) I haven't been keeping up with the newer dev tools that have been released by Bohemia. Was wondering how people have been managing to import fbx into O2. Silly me :rolleyes:

[warlord554 2065]

Looks great! We've done a similar rail on our socmod scar. Do that beast justice with some quality tex/mats ;)

[x3kj 1247]

So manually applying smooth and sharp edges between verts in O2 like Jackal describes, shouldn't really result in too much of a difference from the smoothing groups in Max - it's just tedious to do.

If you select your entire mesh and hit "sharp edges" in O2 every face you selected will have a "sharp" edge to connected faces, including faces that share the same plane with another one - meaning, that the faces will all be split in the game, which would result in worse performance http://www.ericchadwick.com/examples/provost/byf2.html#wts.

If you select every face and hit sharp in O2 you would end up with something comparable to figure 4 in the link.

Edited March 17, 2015 by Fennek

[da12thMonkey 1943]

Yes, but that isn't what Jackal said to do:

selecting the outer edges of the holes and pressing 'U' to sharpen them, will (or at least should) fix the lighting issue you're experiencing.

i.e. the correct way to apply sharp edges to that kind of topology.

You'd have to be pretty daft to just select the whole mesh and hit sharpen.

[x3kj 1247]

You'd have to be pretty daft to just select the whole mesh and hit sharpen.

no shit... i was just highlighting what happens if you select faces (some or all...) and hit sharpen

[WitheringComa 10]

WHat poly count you going for im currently working on a ak op 14

[PuFu 4600]

10-12k verts