XM Magdalena 3D print, GGeorgy (3D)
LC #42 Pipers Alley

View Full Version : selective lighting on instances?

04-14-2004, 02:34 PM
i have a model of a very long stretched tube, which is assembled by repeating segments.
the segments get instanced to be able to render it at all (poly count).

the lighting is done with dmap lights (soft shadows/underwater look).
i initially wanted to use a selective lighting on each of the segments with duplicated lights to be sure the shadow resolution is ok.
but as i try that now, i have to see, that it is not possible to do a light link on instances :/

anyone has a workaround for that besides really duplicating the objects?



pic (2 segments only.. about 10-15 needed):


04-14-2004, 05:43 PM
You can duplicate shaders and link lights to shaders.

04-14-2004, 09:08 PM
i didnīt try but why not just copy all the needed lights and parent them to each segment (10-15) while the objects are overlaying at the same position ?... or just to increase the render time relight the scene with other light sources and give them dmap blur or light angle...

just an idea - donīt know wether it helps or not

04-15-2004, 07:55 AM
Originally posted by augustus
You can duplicate shaders and link lights to shaders.

that unfortunately has the same effect, since maya does not really do the link to the shader, but the shape nodes that use the shader.. and that does not work :/

hmm.. i think i will have to breaking down the elements complexity..
relighting it with raytrace lights is not really possible, since it would lead me to have soft shadows and i can not take these rendertimes at all..

but thanx anyway



04-15-2004, 08:05 AM
that unfortunately has the same effect, since maya does not really do the link to the shader, but the shape nodes that use the shader.. and that does not work :/

Are you sure? I think i did it before.

Edit: I've just tried. It works.

04-15-2004, 08:14 AM
you created and instance of an object, gave that another shader, duplicated a light (not instanced) and then you were able connecting the one light to the normal objects shader and the other light to the instanced objects shader??
does not work for me...
it always selects both of the shapes - the normal and the instanced one..

strange.. am i doing something wrong?



04-15-2004, 08:26 AM
Try this scene (http://www.girisimciliknetwork.gen.tr/ozel/link.ma)

Man i love rendering these little spheres :D

04-15-2004, 08:47 AM
ohh. there is see where my mistake was..
i always tried to light the objects and the shading groups.. that one messed it up.

only lighting the SGs works!!

super thanx augustus.. you helped a lot!



04-15-2004, 08:53 AM
You're welcome:)

04-15-2004, 09:06 AM
even better: this works with sets as well.

like that i dont have to dup all the shaders.. :)



04-15-2004, 09:33 AM
hmm.. both works but the behaviour is a bit unpredictable as it seems..
when clicking around in the relationship editor sometimes it works and sometimes not without that i can see a reason for it..

edit: here what seems to work reliable:
- create your sets for the objects
- open relationsship editor; light centric
- click the "default light set"
- drag deselect all
- drag select all (only gray selectings remain, and no green sub selects anymore)
- select the different lights and in there only deselect the non fitting sets

if you click something somewhere else stuff happens that i can not explain at all.. (e.g.: all looks ok and the same for different lights, but one object is lit, the other not )

04-15-2004, 10:01 AM
You don't break links with shaders, do you?

04-16-2004, 05:52 AM
Just for further info: When you using light link to shading groups method, you don't have to duplicate all shading network. You can just duplicate shading group node (or create new one) and connect your material shader to it.

04-16-2004, 07:47 AM
yeah... i figured that out as well.
but to be honest i better like the idea of using sets in this case.

the rendering from last night seems to have worked out quite well, so thanx again for the tip.
was really vital for me.



04-18-2004, 05:41 PM
95% Offtopic :

Never ever will you get me to drive with one of those things !

Scares me from just looking at this concept :D.

04-19-2004, 07:52 AM

and you will be even more scared if i tell you that the tubes have a vacuum, so the train can drive with 7.400 km/h (makes the way from europe to america in 55 minutes) :)



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