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View Full Version : Controlling Luminance with multiple nulls via nodes?



jeric_synergy
10-14-2013, 01:53 PM
I've been working on a simple logo animation. I used the Node Editor to drop the luminance of the backdrop/cove around the origin.

Now I'd like to do the same thing, to enable just a hint of shadows, but in multiple locations, controlled by nulls (or whatever).

Doing this in ONE spot is a doddle, but how does one combine the effect so that the luminance drop can occur in multiple locations? it seems it would be some sort of OR gate thingymabob....

(Ideally, each null could have a different level of luminance drop, ie #1=20%, #2=37%, etc...0

Sensei
10-14-2013, 05:50 PM
Multiply intensity of null by weight, then add them together, and use Min/Max to get ride of too low/high values?

jeric_synergy
10-14-2013, 05:58 PM
??? I shouldn't have added that last parenthetical comment, 'cuz I still don't know how to have multiple nulls affecting a (spherical) region.

One null is obvious, it's just distance and a SPOTINFO node. But if there's multiple nulls, I'm clueless.

tbagger
10-14-2013, 07:16 PM
??? I shouldn't have added that last parenthetical comment, 'cuz I still don't know how to have multiple nulls affecting a (spherical) region.

One null is obvious, it's just distance and a SPOTINFO node. But if there's multiple nulls, I'm clueless.

Also remember that gradients have background inputs that can be other gradients, and their keys also allow for opacity.

jeric_synergy
10-14-2013, 11:10 PM
Okayyyyyy.... trying to wrap my head around that...

So, what I need is a network that says "If you're spatially close to THIS(1) OR you're close to THIS(2), then adjust your {luminance} as per {various numeric methods}."

I guess it's time to watch RH's node tutorials (I bought them!) again....

{examining the Gradient Node} Perhaps the fact that there are Blending options between the BG Color and the Gradient will implement the OR section of this puzzle. thinkthinkthink

tbagger
10-14-2013, 11:32 PM
Okayyyyyy.... trying to wrap my head around that...

So, what I need is a network that says "If you're spatially close to THIS(1) OR you're close to THIS(2), then adjust your {luminance} as per {various numeric methods}."

I guess it's time to watch RH's node tutorials (I bought them!) again....

{examining the Gradient Node} Perhaps the fact that there are Blending options between the BG Color and the Gradient will implement the OR section of this puzzle. thinkthinkthink

His vids will definitely help figure it out,... here is quick setup if you dont feel like searching. Could use blending modes as well depending on what you are going for.

jeric_synergy
10-14-2013, 11:57 PM
Damn you're good, Bryan.

I see what you are saying now: the lowest gradient in the totem pole of evaluation is opaque at all values, while the subsequent gradients evaluating other null controllers have transparency in them, and thus can be overlaid on the first without affecting the resultant final composite gradient result.

It still makes my mind hurt a bit when I try to conceptually relate the gradients to the spatial expanse of the mesh, but I'm getting there.... I can almost imagine a network that uses just ONE gradient and slides keys themselves up and down the gradient.... almost.... ouch....

Many thanks! Very impressive.

+++
(not getting too far... what would be an application where one moved the gradient keys around? We have that capability, and I think I saw it used once...)

tbagger
10-15-2013, 01:43 PM
+++
(not getting too far... what would be an application where one moved the gradient keys around? We have that capability, and I think I saw it used once...)

That is actually one of the great features with LW gradients. There are a ton of things that can be done with it. For what you are doing here you could use another null to determine the radius of you distance. So one null control center and another would control the radius. You would get the distance between the two nulls and drive the position of the key.

jeric_synergy
10-15-2013, 06:55 PM
Yesssss! Any effect that can be modulated by moving keys 'manually' can be animated by connecting nulls to key pos inputs.

THe effect I'm very vaguely remembering, the network sort of ignored the nominal input but the moving key did the work. Wish I could remember what it was: it REALLY confused me for a long time.