How to use a Object Labels pass?

[Anonymous]

I have a couple of questions about how to use object label pass or idmatte, for to isolate a specified region.

Well, first I explain my situation. In Softimage XSI, the object label pass is by default saved how .tt (MentalRay Label) format. Also it saved how .map (MentalRay Map). Both are 32-bit float point and label type formats.
I use Combustion and Fusion for my composites and, these formats are not supported in my favourite compositing software. Then, I try saving object_label pass in RGBA .pic and also in 32-bit openEXR (thinking maybe another 32-bit format, would be include the additional information like that Id tag).

In the practice, with Combustion I can use object_label_pass.pic or another 8bit/16bit RGB format, by means of G-Buffer Build and G-Buffer Extract operators, ‘extracting’ IDtag from plain color to integer valule.

With Fusion, I don’t see how to use object_labes pass for make matte. I thinking in use a keyer operator for “erase” a color from object_label, and convert to a tipical white_matte but I don’t be sure about this is correct.

My questions about this:
1. Anyone knows a tutorial to explain how to use Object_labels or IdMatte in Fusion?

2. Object Labels pass is aliased. I think this is logical because ObjectID is pick from a integer
value color, and if would be anti-aliased only the boundaries have a few color values.
But, because Object_Labels pass are aliased, how to make a matte outline smooth? I try with a Matte control operator but is not useful because forced to remove matte outline shape.
What’s the solution for this issue?

Thanks.

Unaided

P.D. I attatch two screenshots with a real object_label pass and the other fake_object_labels pass, build with a constant material, how to simply solution for rendering with anti-alias this pass.

[Anonymous]

Well, I find this videotutorial, and is exactly I was going search.
http://www.digitaltutors.com/store/video.php?vid=1449

I only adding the Pixel Coverage pass, connecting to a Bitmap Mask set luminance channel, and this connect to operator in use of th object_label pass. With this the pre-multiply pixels of coverage are added to object boundaries masks.

[Author]

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