linking luminace value to scale

[Dan Ebberts]

Something like this should work:

minScale = 0;
maxScale = 100;
L = thisComp.layer(“displacement image”);
sampleSize = 1;
point = L.fromWorld(toWorld(anchorPoint));
sample = L.sampleImage(point,[sampleSize,sampleSize]/2,true,time);
lightness = rgbToHsl(sample)[2];
s = linear(lightness,0,1,minScale,maxScale);
[s,s]

Dan

[Criis Daw]

Thanks Dan,

I think i can get my head round it. Did you just write that ?
I am very impressed…

[Dan Ebberts]

I did. But I’ve had a lot of practice…. 🙂

Dan

[Criis Daw]

well its working….

but the x and y are scaling and the z remaining the same. Its the reverse I am after.
I am tying to work it out but ……

[Dan Ebberts]

Sorry – that’s what I get for reading too fast. Try this:

minScale = 0;
maxScale = 100;
L = thisComp.layer(“displacement image”);
sampleSize = 1;
point = L.fromWorld(toWorld(anchorPoint));
sample = L.sampleImage(point,[sampleSize,sampleSize]/2,true,time);
lightness = rgbToHsl(sample)[2];
s = linear(lightness,0,1,minScale,maxScale);
[value[0],value[1],s]

Dan

[Criis Daw]

Thanks i worked it out !
well almost .

i changed the last line to

[50,50,s]

and typed in suitable x,y values (50) and it works like i want.

what does the command (value) meam / make it do ?

thanks for your help.

[Dan Ebberts]

value just retrieves the pre-expression, keyframed (or static) value. So if you set the scale of the layer to 50%, both versions should give you the same result.

Dan

[Criis Daw]

thanks for your help

little by little I am getting better at them.

I can even more or less understand the body of the one you sent me. Its a bit like learning a foreign language. Reading often comes more easily than speaking (well correctly at least) .

again many thanks

Chris

[Anton Arkh]

Hello! I am a complete novice when it comes to expressions, so I have no idea how to create anything more complex than a wiggle expression.

How easy is it to adapt this code that Dan wrote to a lens flare brightness? I have a black/white image that I want to use as a mask, so when the Flare Center is over the white area, the Flare Brightness goes up, when its over black, it’s at 0%

Thank you very much in advance!

[Dan Ebberts]

This should work:


minBrightness = 0;
maxBrightness = 100;
L = thisComp.layer("your mask image");
sampleSize = 1;
point = L.fromWorld(toWorld(effect("Lens Flare")("Flare Center")));
sample = L.sampleImage(point,[sampleSize,sampleSize]/2,true,time);
lightness = rgbToHsl(sample)[2];
linear(lightness,0,1,minBrightness,maxBrightness);


Dan