View Full Version : "See Through" Baked UV Map

02-07-2014, 06:22 AM
First time using the Surface Baking Camera in 11.6.1, but it seemed like a no-brainer...

Create a global UV map of my object and one for the ground (in addition to all the other UV maps to initially image map it). Note: I didn't tweak the UVs of the global atlas map as this was just a first time test to learn what to do, etc.

Load into Layout, set lighting and GI (in this case low GI to get an assumed speedy render, so 250 rays, 2 bounce, 25 sec. rays, interp. MC, use gradients, ambient occlusion, no behind test, and 2 x 100 pixel spacing at 45 deg).

Render using Surface Baking Cam set to global UV map, 2048 rez, 1mm offset (not sure what it's for, but 0.1mm seemed really small for the scale of my object, which is 250 x 175 meters or so).

First try with AA = 4 x 32 took hours to even get close to finishing the first pass. Also, GI pre-calc was super fast... 15 sec. So I cancelled the render and turned off AA and set Min. Samples to 1 to speed things up. 4.5 hours later I had a map, though that time seemed too long for such low-quality settings.

I then applied the baked map to a duplicate model with just the global UVs (removed all other UVs and images) and was horrified to see "see through" walls and several poly faces totally black and unrendered per the attached image.


The geometry of the highlighted outer walls are 'water tight' (if that matters). The model has NO orphan vertices nor any 1 or 2 pt polys. It's a very clean model with only a few small details not booleaned or point-merged to the main geometry. The outside walls highlighted are not connected to the inner walls. The towers are not connected to the rest of the model, etc. The inner walls, floors, and roofs are one mesh and is not water tight (uncapped walls where they meet the main outer wall, etc).

And just to be clear... it's not just the outer walls that have this 'see-through' effect... several of the interior walls do as well and many of the faces of the towers in the distance have those rounded-corner "holes", too. You can see a couple of them on the upper left tower.

Any help?

02-07-2014, 07:29 AM
When renders for baking take too long, stop them and up the UV border on the surface baking camera. I've had to go as high as 100. If it still not working make the UV again and sometimes that does it. Make sure all your geometry is triangles, or at least that you don't have nonplanars. Other things that can screw the baking are 1 and 2 point polygons, overlapping geometry, and having two polygons in the same UV space.

To avoid the black lines on the seams, render it again with no GI, turn off lights, shadows, transparency and reflecitons, lower the UV border to 0, and save out just the alpha. Use this alpha to make a mask for your color image, and use "content aware fill" in photoshop. this will fill the black areas with color from your texture.

02-07-2014, 09:13 AM
Maybe my tutorial can help you:

Remember always bake triangulated object.

02-07-2014, 04:00 PM
Remade the global UV map and tweaked the blank out of it. Probably achieved around 10% or so of unused space. Tripled all major polys (didn't do all the teeny weeny ones). Yep, that did it! GI took it's time pre-calcing and the render was lickity-split! UV border set to 20 took care of most of the black fringes. But more important... no more "see through" baked UV textures. All walls are nice and solid looking now.

Thanks, Danner, for those VERY helpful tips!

02-07-2014, 06:17 PM
Offset for hundred meters object should be much bigger than 1mm. You need to increase it, quick F9 with low-res, see whether it's fine, if no increase again, F9, repeat. Experimentally. Couple times.

BatchBakingCamera can be hundred percent times faster than native LW baking camera

If LW renders on Core i7 in 60 minutes, BatchBakingCamera can do it in 8 minutes.