Hi guys,
Does anyone know of any other ways of controlling particle size other than ‘Size randomness’ and ‘Scale over time’? I’ve hunted through all the shading nodes and the image affector only appears to be able to offset them. Is it possible to have the luminance of an image affect particle size, for example?
If not, could this be implemented in future?
Cheers
Hey Nick,
This might be what you’re after. To quickly give it a test, I’d suggest use alpha as scale on a Point Renderer and see if you get the desired effect? (second tip: the Size Curve underneath can be used to control the range of sizes you want)
Cheers man, will give this a go! 
Hey Bent, struggling to get this to work tbh. I’ve attached an example DFX, if you could help me out or point me in the right direction that’d be awesome.
Basically i just want the luminance of the image in the DFX to scale the particles relative to their luminance, or something similar (obvs white 100% scale, grey 50%, black/dark grey 0-5%).
Would be much appreciated!
Cheers
Example.dfx (617.4 KB)
Is this what you’re after? If so, I got it working by using an image emitter instead of a mesh emitter, as well as fixing the alpha properly in Photoshop and creating a PNG with transparency (the second step might be redundant).
For …reasons… I can’t post an image of my node graph or the DFX though.
Nice! Thanks yeah I can see that working now!
The reason i was using the mesh emitter was so i could emit across a plane, almost creating a grid-like effect, see below using Stardust. Is something like this achievable using the image emitter?
Will be my last spam i promise 
Cheers
Hm, shouldn’t really be a problem to do that via a render to texture and slapping that on an image plane. But, if that’s the effect you’re after (and don’t need particles for depth), won’t http://manual.notch.one/0.9.23/en/topic/nodes-post-fx-stylisation-dot-matrix do (and be a lot cheaper)? It can scale by color/intensity.
Like so (glow added, because… well… glow)
That’s the effect i was after, but would be cool to be able to add turbulence, etc, which is initially why i went for the mesh emitter, and would add deformers after.
Would be a welcome addition adding particle scale to the image affector in future. If at all possible.
Thanks Bent
Think i pretty much nailed it - it’s just a case of limiting the emissions per pixel in the image emitter, then down-sampling the input, with the setting ‘point sampled’. It can now work with turbulence, etc.
Just thought I’d throw this in here if anyone else is interested.
That’s a solid solve!
Can You mark answer as a solution?
It already is. Doesn’t it show up for you?
Sorry, now I see it
My mistake 
