Blender - Exporting Correctly Smoothed Low-Poly/Cage The Easy Way!

cookedpeanut

Hi guys,
I quickly created this video as it explains a way of working around the smoothing group limitations of Blender.
This method should ensure perfect bake exports!

Video ends at 9:30
Hope it helps

[ame="http://www.youtube.com/watch?v=n9Kx_Jc35zc&feature=player_embedded"]Blender 2.68 - Exporting Correctly Smoothed Low-Poly/Cage The Easy Way! - YouTube[/ame]

Dashiva

Cool. Andy Davies also has a way to do this that sort of goes along these lines:

http://www.polycount.com/forum/showpost.php?p=1637437&postcount=6

I can confirm personally that the smooth/hard edge code in the new .fbx exporter works right, but we're still waiting on the .obj exporter.

http://blenderartists.org/forum/showthread.php?291881-Exporting-OBJ-and-FBX-physically-break-edges-no-love-for-the-game-making-community

is where that is happening.

mAlkAv!An

Obj exorter has been updated first:
https://projects.blender.org/scm/viewvc.php?view=rev&root=bf-extensions&revision=4753
(This is for split vertex normals, smoothing groups was already in before)

Nosslak

This is kind of basic stuff so I think most people probably know about it already. Otherwise I thought it was pretty good, could maybe have been a bit shorter though.

However I did find one case of misinformation in your video. You mark all of the seams as sharp when it really should just be the other way around (all hard edges should be seams, but not all seams need to be hard). If you were to do this on a cylinder you would get a hard edge along the UV-split which would be sub-optimal as then the normalmap would need to compensate for that and you'd get an unnecessary gradient there.

cookedpeanut

Well I've used Blender since 2010 and have always had trouble with efficiently exporting the low-poly model with the right normals/smoothing groups. As far as the Blender Wiki is concerned, it doesn't explain this procedure there.
So fair enough if people "should" know it - I didn't :P

As far as the technique is concerned though, it's far easier to use this method and THEN tweak the sharp edges by adding or removing hardened normals, so either way it's a win-win scenario.
Just thought I'd make a video on it as there hasn't been one that explains it well.

P.s. Video wasn't scripted so if there were errors then mybad

Thx for the .OBJ exporter link BTW! Will give that a go

Nosslak

Yeah, I agree, it can be a good starting point, I just meant that it didn't say anything about that in the video. From the video it looks like that is all that is needed.

'Seams From Islands' doesn't work well with stacked UV islands where the islands touch each other on the model either, which might also be good to keep in mind.

cookedpeanut

Seams from islands is only used as a lead-up to selecting the mark as sharp feature... You could always select the entire mesh and clear seams once the edges are marked as sharp :P