View Full Version : Object ID Render question

11-15-2017, 02:52 PM
I set up a simple scene to test some buffers I want to use in a larger more complex scene. One of the buffers I set up in the Compositing Buffer Export panel is Object ID. Upon rendering I get my expected Object ID render as shown in the screen shot.
But when saved and brought into PS I get this:
What is going on? :) I've tried saving the image in several formats all with the same result. What am I missing or don't understand? I thought I could use the Object ID pass for masking various whole objects of my scene inside of PS. Thanks.

11-15-2017, 04:45 PM
What bit depth are you using? I'm not sure but it might not work properly with 8-bit.

I use EXR with floating point and it works fine here in Fusion. Well, except for AA because LW doesn't have a Coverage buffer yet. You can cheat the AA in comp but you might get a slight fringe where Object/Material ID's overlap.

If I have overlapping selections, I usually create an RGBA matte pass instead so I don't have to worry about the AA. This essentially gives you four mattes in one render with correct AA for selection. It's kind of a low-tech version of Object/Material ID but it works great from LightWave. It renders fast too since lighting and shadows is not needed (just turn all your raytracing features off). I think I described the technique in the Brudders thread a few years ago. I don't remember exactly what I wrote so if you have questions, feel free to ask.

BTW, Vue can output Object/Material ID and Coverage, which works great in Fusion. There are a few hoops you need to jump through but once you set it, it's pretty awesome. You just enable the material and/or object you want to select in a bitmaps mask, and Fusion automatically applies correct AA if Coverage is also available in the image. I keep hoping LW will get this too...I know the devs are aware so fingers crossed. :)