Action Lens Flare question

is it possible to drive an Action Lens Flare using the brightness values from a surface?

I have an animated matte channel that i want to be seen by the lens Flare as the light source…i have a feeling its not possible, but i’m open to suggestions.

I’ve always thought it was driven by a light - sapphire lens auto track can use luminance though.

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I tried connecting the surface in place of the light and got nowhere fast…I don’t think you can’t use Sapphire inside Action.

Made a great alternative using the Physical Glow added to the camera to flare out the matte animation.

You should be able to link the transparency channel of your surface to the brightness parameter of the flare.

Yes its value is also inherently linked to the light source but that just gives another level of control.

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Something I’ve always considered doing but never achieved: can you link the transparency of a layer to a luma key?

Let’s say you use a YUV key or a 2d historian - can you link those numbers measured by flame on the histogram to a transparency of a layer in action or any other value via expressions? In my head it should work but I’ve never figured out how to do it.

I don’t think the key color you pick is revealed as a channel that you can link to. Maybe it’s possible to link the in/out values of a 2D histo.

I don’t think you can’t use Sapphire inside Action.

The Sapphire OFX works in Modular Keyer if your matte channel is coming from a media import. Would only be a fixed flare layer sadly through this but maybe helps.

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There used to be a matchbox that could sample a colour/value - I can’t for the life of me remember it - but I wondered if this was tracked to a stabilised portion of a plate then that number could be linked?

i keep meaning to play with the modular keyer…i tried it 7 years ago when first starting on Smoke and found it confusing, but then everything in Smoke was confusing me!

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A feature request would be to read the rgb value of a pixel, area, average color of a frame and return it as a linkable parameter.

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The best I can think of is to output the surface and flare separately, meter the flare’s source point using the “y_sample” matchbox, then multiply the fullscreen result of that back over your flare.

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Hey Adam,

A couple of things come to mind, not sure if either will do what you need:

• Your animated matte, negate it and use it as a flare occluder surface in Action. This will allow the Flare to bloom only when & where the matte opens up. You can add a matte edge to the incoming occluder surface to shrink/blur/erode the occluder to taste. Also mess with the occluder size in the flare. You would still need to track your flare to where it needs to be.

• You could try using glints rather than a flare – though depending on the kind of optics you need, this may or may not be suitable. The benefit is that the glints will automatically only bloom when & where the matte is, and there is no tracking. But they’re not real flares. I often get the flare look I need with glints for fast work, but not always.
I would try ls_glints or Sapphire - they’re both great. Or in Action, Physical Glare.


Thanks GP - nice ideas…will try them out for future.

i ended up doing it with Physical Glare as i was able to get the style i was thinking of, along with a few gmasks and Matte Edge to extract a clean outline
CO FlareFX

the gif encoding makes it a bit crunchy, but you get the idea…

Have you ever tried LS_Glints or S_Sparkles with Crok Beer as the source element? Makes fantastic sparkly textures.


I have not, but I could actually use that today. Thanks!

from my One Frame of White …

the sapphire one is better because you can select affect alpha and it adds the sparkles into the alpha channel as well - letting you get the overlaps at the edge of your mask.


Very cool.