Expression for color control

[Filip Vandueren]

For versatility and easy tweaking, we’ll store the colors in a control layer:

Create a Null object called ‘Colors’
Add as many “Expression Controls -> Color Controls” to that as you need.

Add this expression to the color you want to control (probably the fill of your shape layer):


l=thisComp.layer("Colors");

// retrieve colors stored in the color controls
i=1;
colors=[];

try {
while(l.effect(i)) {
// an effect exists, but is it a color control ?
// We'll check if it's first parameter is called "Color"
if (l.effect(i)(1).name=="Color") {
colors.push(l.effect(i)(1).value); // store the color in a list
}
i++;
}
} catch (e) {}

// Now if the list of colors contains any elements
// we will get a random value from the list.

if (colors.length) {
r=Math.floor(random(colors.length)); // a random integer
colors[r]; // return the color

} else {
// the list of colors is empty, so we use the existing color value.
value;
}


This expression will change the color every frame.
Perhaps not what you need, so let us know what you want to do with the random values.

[Pierre-alexis Tremblay]

Works fine! Thanks a lot.

[Gabriel Netto]

I’m an expressions newby so…
Could someone help me with this question?

I’m working on a CARD project based on 4 variables (CS3). As you will see they are on an external txt and code is located on a text layer. I’m using “Hoyle Playing Cards” font symbols and that’s why they need to change: s = “q” (s for spades is q character, etc.)

My problem is that I need to alternate between red and black font colors. (spades and hearts have to be red, spades and clubs have to be black) but I just can’t figure out how to change this colors using expressions… I’ve tried to use fill but I don’t know how to set it’s color property via expressions.

Maybe a Color Control or a sampleImage() effect?

Any help is really appreciated!!!
Thanks in advance!

Gabriel Netto

//Here's my code:

s = "q";
c = "w";
d = "e";
h = "r";
eval(thisComp.layer("LER_TXT").text.sourceText.value);
myPath = "/MyHD/Prog1.txt";
try{
$.evalFile (myPath);
eval(thisComp.name)[1];
}catch (err){
"not found"
}

[James Hawkins]

This is a great technique! But what would one need change in order to have it hold the chosen color for the duration? Rather then change every frame.

[Dan Ebberts]

Just make this the first line of the expression:

seedRandom(index,true);

Dan

[Jarek Borzecki]

Hi All,
i’m completelty green with svripting, really appreciate if you can help me as well.

In main comp i’ve created null object with expression control>color controll, and there are two effects ‘fill’ for example ‘font1’ and ‘font2’
i want to change color for font1 in this comp – this is working fine for me, but i have problem when i’m trying to controll color for font2 inside another compostition..is it possible or can i only controll colors/effects by expressions inside the same composition?

thank you for your help
J

[Dan Ebberts]

You have an expression for Fill effect Color in the other comp linked to the color control in the main comp, is that correct? That should work just fine.

Dan

[Jarek Borzecki]

hi Dan,
correct,

!Main_Composition with Colour Control layer (my null object) and Artwork Colour – my fill effect

and another comp ‘WMan’ with fill effect

I’m receiving this error:
Error occured at line1.
Comp: ‘Wman’
layer: 2 (w1_ai)
Property: ‘Color’

comp("!Main_Composition").layer("Colour Control").effect("Artwork Colour")("Color")

[Jarek Borzecki]

hi Dan,
correct,

!Main_Composition with Colour Control layer (my null object) and Artwork Colour – my fill effect

and another comp ‘WMan’ with fill effect

I’m receiving this error:
Error occured at line1.
Comp: ‘Wman’
layer: 2 (w1_ai)
Property: ‘Color’

comp("!Main_Composition").layer("Colour Control").effect("Artwork Colour")("Color")

[Dan Ebberts]

I just tried it with your comp, layer, and effect names, and it works fine for me. I have no idea what it’s not working for you.

Dan