light instancing

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hey …

Today i wanted to do some light instancing in Houdini 10 but i can't figure out how this is working. I searched the forum and finally found a video tut about this subject that was done in Houdini6, but i can't apply the technique to my houdini 10 version.


In fact the shader SOP (that was used in the tutorial) in my scene doesn't work at all, it gives the following warning
“this SOP is deprecated in favour of the material SOP”.
even if i turn on “generate point attributes for instancing” and chose a light shader in the “lightshaders/light” tab it won't work.

ah and of course i told plugged my geometry into an instance node and enabled “point instancing” also chose the light as the instance object.

it would be great to get a hip file how light instancing can be done or a quick walkthrough, that would be very nice of you advanced houdini users )

well wish you a good night,

Manuel
http://vimeo.com/user2522760 [vimeo.com]
http://stormbornvfx.com/ [stormbornvfx.com]
Manuel Tausch
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asnowcappedromance
hey …

Today i wanted to do some light instancing in Houdini 10 but i can't figure out how this is working. I searched the forum and finally found a video tut about this subject that was done in Houdini6, but i can't apply the technique to my houdini 10 version.


In fact the shader SOP (that was used in the tutorial) in my scene doesn't work at all, it gives the following warning
“this SOP is deprecated in favour of the material SOP”.
even if i turn on “generate point attributes for instancing” and chose a light shader in the “lightshaders/light” tab it won't work.

ah and of course i told plugged my geometry into an instance node and enabled “point instancing” also chose the light as the instance object.

it would be great to get a hip file how light instancing can be done or a quick walkthrough, that would be very nice of you advanced houdini users )

well wish you a good night,

Manuel

Generally speaking you instance lights the same way as you instance geometry in H9&10 - using instance Object and pointing it to light object to be instanced. The tricky part is, when you want to overwrite instance's shader properties. You use material sop with attribute overwrite toggle as shown in example file.

Basically the workflow is to create attributes on points with desired values and the same names as attributes on shaders (default Houdini's light uses vex asad light shader, thus I know I can use it in Material SOP).

hope this helps.
cheers,
skk.

PS In case of shadow maps you will have to use `instancepoint()` expression in shadow map path it vary it on per instance basis.

Attachments:
instance_lights.zip (30.2 KB)

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hey, you guys rock, thx a lot !!!
that was very very helpful !!
http://vimeo.com/user2522760 [vimeo.com]
http://stormbornvfx.com/ [stormbornvfx.com]
Manuel Tausch
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