Link Ramp color to Ramp Position

[Kevin Camp]

you can use sampleImage() to sample a color of a layer.

something like this may work in the ramp color property (start point):
target=thisComp.layer("boat"); // the layer you want to sample the color from
p=toComp(effect("Ramp")("Start of Ramp")); // sets the sample point as the start ramp point
r=[.5,.5]; // radius of the sample point
target.sampleImage(p,r)
to set the end point color, you would apply the same expression to that property and change the ‘p’ variable to the ‘End of Ramp’ property.

if you needed more color variation, you could try the 4-color gradient effect and apply the same expression to all 4 color properties.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Achille Abboud]

Thank you Kevin. It is working perfectly.

Now I would like to ask you how to delay the changes, because now that it is working, I would prefer to change the color every -lets say- 10 frames.

If I would change the Radius Value, would it give the average of the color that is in the Pixel amout?

so if I wrote r=[10,10];, would it be the Average of a 10 SqueerPixel Value?!

Thanx again,

Achille

Greetings from Berlin,
Achille

[Kevin Camp]

[Achille Abboud] “if I wrote r=[10,10];, would it be the Average of a 10 SqueerPixel Value?!”

yep… that can help to average out the color change.

[Achille Abboud] “I would prefer to change the color every -lets say- 10 frames.”

i can’t test this right now (too much rendering going on), but i think you might be able to use posterizeTime() to get something like that…

try adding this as the first line of the expression:

posterizeTime(3) // the value in () is in frames per second

if that doesn’t work there is a time component that can be specified in sampleImage() and we could probably figure out a way to manipulate that.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Darby Edelen]

[Kevin Camp] “if that doesn’t work there is a time component that can be specified in sampleImage() and we could probably figure out a way to manipulate that.”

This seems to work:

n = timeToFrames(time) / 10;
t = framesToTime(Math.floor(n) * 10);
target.sampleImage(p,r,true,t);


If you don’t want any jumping in the color you could apply just the first two lines of this expression to a Slider Effect (under Effect > Expression Controls), then link that into the sampleImage() expression with a smooth() method attached.

Applied to “Slider Control”:

n = timeToFrames(time) / 10;
t = framesToTime(Math.floor(n) * 10);

Then this becomes the last bit of code for the ramp color:

t = effect("Slider Control")("Slider").smooth(framesToTime(3), 9);
target.sampleImage(p,r,true,t);

The above will smooth the transition in color every 10th frame over 3 frames.

Darby Edelen