View Full Version : primary visibility "off" to catch shadow

12-10-2009, 11:01 PM
Hi everyone!

scene: A complex object (animated, a helicopter for example) - composed of a groups of surfaces parented under a controlshape - casts shadows onto a ground plane, that has mip_matteshadow on it with an mib_color_alpha plugged into the backround. The scene is rendered with mentalray.

I would like to render the shadow (and its alpha) that is cast onto the plane without rendering the object itself.


1. Normally I would switch off primary visibility on the object. But since the object consists of a few groups containing lots of surfaces/objects, I will have to jump into every single shapenode to turn off primary visibilty. How do I turn off primary visibility on all the subgroups at once?

2. Is "primary visibilty" the correct approach? If I use a shadowpass instead, How do I render ONLY the shadow on the groundplane, WITHOUT the shadows, that the object casts on itself?

I did a few tutorials on the subject of renderlayers/passes, but somehow none of those covered this exact situation.


12-10-2009, 11:16 PM
If you want to turn off Primary Visiblity on all those objects quickly, use the Attribute Spreadsheet (Windows -> General Editors -> Attribute Spreadsheet) Select all your objects any way you choose (via the entire group or individually) then open the AS, navigate to the "Render" tab, and then click on the words "Primary Visibility". Type "off" and hit enter, and you're set.

12-11-2009, 12:35 PM
Thanks a lot, exactly what I was looking for!

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