hi! Is it possible to control light intensity (or other parameters) with geo nodes?
I managed to scatter some light with geo nodes, but I am not sure it’s possible to control their parameters? Any ideas? THanks!
It’s not possible, GN only deals with geometry ATM, meshs, curves, points clouds, volumes (maybe ?) …
You may try animation nodes, I’m not sure it’s possible with it but there is better chances.
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thanks… yeah it looked like it’s still not a supported thing. I’ll check AN, thank you!
btw, do you know if this kind of functionalities are planned for the future of GN?
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Maybe in a far far future, the final goal for blender is “everything node” , but for now there is so much to do with geometry only… And this tool is called geometry node after all. Maybe at some point there will be a broader way to manipulate different data with nodes inside blender. Still a very long road…
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I wonder if you can pin a empty to a vertex*, and move the empty with geonodes, and use the empty pos as a driver in the lamp settings?
edit:
needs_missing_update.blend (839.7 KB)
It works when I manually move the empty, but not when the geonodes move the empty
I think the driver is missing a depsgraph update
Hum, I think when passed through a GN network the empty doesn’t exist anymore.
It’s part of the resulting GN modifier that contain geometry, instances, curves, ect… but it’s a whole and not independent objects anymore.
It’s like joining two objects in GN, the objects doesn’t exist anymore and are part of the original object with the GN tree. You can move these objects within the tree but the result will always be an object.
Because GN deals with “mesh data” like modifiers , rather than object data like constraints. You can get object data as input, but not output them.
One solution could have been to , instead of instancing lamps instancing points with attributes, and use something to convert these points to lamps and use the attributes to drive the settings. Maybe AN can do that, or a python script.
I think it’s part of the design of GN that fit well the idea of a nodal modifier. Being able to modify object data is part either of something like “Object nodes”, something like nodal constraints. Or something bigger like animation nodes than as a broader scope.
When you manually move the empty it changes the location of the empty, while moving it in the geonode changes the position. Not sure what the difference is, but it evidently does something.
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If you are using cycles, you always have the option of storing attributes on geometry(spheres, planes, disks), and using full emission lighting. Of course, this is not as ideal as using lamps, but it’s a lot less limited.
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You mean using geo shader emission? I thought about that and I’ll give it a go, although I’m afraid it’s gonna be too heavy, since I have a lot of lamps. Thanks!
Too heavy in what regard? I just did that for a LED strip can turn on and off individual LEDs. I rendered with 220 or so individual LEDs and it worked fine.
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shader based emission will be much less impactful with a lot of light sources.
each lamp has overhead, and the more lamps you have the more noise you will have in your scene.
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Sometimes Empty behaves just like a single vert, other times it does not. It is very inconsistent 
I was for some reason convinced that shader emission was heavier… looks like i was wrong! I’ll definitely try, thanks!
In certain circumstances, lamps are better, but if you are looking at hundreds of light sources, the overhead outweighs the efficiencies
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