Getting correct bakes from Blender

anaho

Hello, I modell in Blender and want to bake with xNormal.
However I always get ugly seams where my UV seams ( and hard edges) are.
What I do:
1.) Set the Lopo up correctly so that it looks right when smoothed
2.) Break the UVs on the hard edges and place them a little bit away from each other
3.) Load the Hipo and Lopo up in XNormal
4.) Get this result Baking in Blender doesnt change this error.

http://imageshack.us/photo/my-images/201/gaddee.png/

|MM|

I remember trying to get that nice smooth edge effect on my bakes in Blender and couldn't get it either.
Now, I did a test and the same meshes give a great result in 3ds max while beeing broken in Xnormal and Blender.
Obviously I set up the proper tangent basis for each.

anaho

Did you use the cage option when you used xNormal when you used Blender? Thats one part of xNormal I dont really understand.
Maybe this has to do with way how set up "smoothing groups" in Blender altogether.

|MM|

I don't think it has to do with cage and in Blender I used edge split to keep the groups separate.
The difference between 3ds max's bake and others wasn't that big on the other hand
and note that you'll always have some artifacts from a very short distance.
As to the cage in Xnormal I've had some hard time trying to get a hold of it but
now it seems pretty intuitive just remember to use "save meshes" in the viewer otherwise the cage is not set i think.

Zwebbie

What it looks like to me is that the rays from the top plane go along the Z-axis and catch the entire edge, while the front plane catches the entire edge as well, which means you have it twice now. Like with the cyan asterisks in this image: Normal map raycasting. I'd have no idea why that would work in Max, though.

anaho

Hope that there is a solution for this at all.

anaho

I did some further research on this but this things do not look good: 1.) If you set your Lopoli smooth before you bake and have NO hard edges set you get some nice smooth corners around your edges. (The Lopoli is set to smooth after the bake as well) http://imageshack.us/content_round.p...moothedlop.png Even though this looks good on this simple object,this introduces shading problems on more complex objects, obviously. 2.) If you set your Lopoli up "correctly" with appropriate hard edges ( edge split modifier) or just break them of manually or use flat shading, you get "no" shading issues in the usual way, but introduce the nasty edges. ( Pic also has AO bake) http://imageshack.us/photo/my-images/19/smoothedbakesmoothedlop.png/ Conclusion for now: Stay away from the edge-split modifier and rather add more loopcuts to the lopoli. However this has some pretty serious impact if you are creating game assets as your vert count increases. Solution: I dont know what the problem is but to me it seems either breaking of geometry ( which is exactely what the edge-split modifier does as well) is to blame or there is a bug in the baker. Please post feedback as this is might be a bug or at least a serious drawback and maybe should be made aware to the coders.

EarthQuake

Blender splits the projection mesh along hard edges. This is the source of your problem.

Max uses an averaged projection mesh(cage) unless you specifically turn it off(use offset).

Xnormal by default uses a simple ray distance from the mesh normals, which like blender results in split normals along your hard edges. You can set up(in the 3d viewer) or import a custom cage mesh in xnormal though.

read this entire thread: http://www.polycount.com/forum/showthread.php?t=81154

Unfortunately I do not know if there is any way to get an averaged projection mesh in blender, or if you can even export a custom cage without split edges to use with XN from blender. I would suggest simply using Max or Maya to bake, or at the very least to set up your cage and export it to XN.

anaho

Okay that was quick. How does Maya handle it then because I thought it used nearly same same way of splitting vertices of as Blender. Probably dumb question: Where do get a cage that you could import into XNormal from? Thanks, that was very informative.

EarthQuake

Maya has a quick toggle that lets you switch between the two methods, I think its the "match using" option, but I dont have maya here right now to take a look.

When you install Xnormal it installs a Max plugin so you can export in .SBM(xnormal format) and includes options for exporting the cage. I assume there is a similar plugin for Maya but I haven't used it.

Xnormal has an option to load an external (obj or whatever) cage file too, but the vertex index has to match up, so I'm not sure you can do that straight out of blender.