I have a situation where I have instanced lights and want to have a shadow shader….is this possible? I am getting some weird artifacts when I try to use shadows.

Im guessing its because you would have to have a shader for each light normally….along with a z-depth map per each light. Is there a work around?

:shock:

You have to have a zdepth map for each light if you're using zdepth shadows. This has been covered before in this thread:
http://odforce.net/forum/index.php?showtopic=1724&st=12 [odforce.net]

(which I found via search here on this thread:
http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=4230&highlight=instancing [sidefx.com] )

You could always just choose to use ray-traced shadows if you want to avoid the management of it.

Thanks for the help Edward…

just a couple things I noticed in the BasicExample.hipnc….which came from http://odforce.net/forum/index.php?showtopic=1724&st=12 [odforce.net]

1) On the AreaLight geometry(the points obj to instance the light to):
in the Shading Tab>RIB Tab> Transmission Visibility is checked on, and set to Visible - Use Cs/Os
what is this? I checked it off and didn't notice any difference…

2)The VEX Shadow was set to its default using Fast Shadows…I tryed applying Deep Shadows,
*I used $TEMP/shd$IPT.picnc for the Z-Depth map to match the Light Obj's Z-Depth Map…
*turned on Deep Shadow generation…
*Changed the type from zdepth to deep in the string in the attribCreate for the shadow shader

anything I am missing? The deep shadows produced shadows all over the grid…blownig it out totally black around where the objects were.


any help is appreciated!

I didn't look at the file too closely. The RIB parameters are for Renderman and so it has no bearing on the Mantra render. There's no reason that I can see for using deep shadow maps in this case. Did you make sure that the zdepth map's were generated (eg. turn on auto-generate shadow maps) ? I think there's more in the Light Instancing tutorial as well. Make sure you read both threads.