Making an object change color every 90 degrees

[Dan Ebberts]

You only need to use radians if you use JavaScript’s trig functions. For what you want to do, degrees should be fine. This will increment every 90 degrees

Math.floor(transform.rotation/90);

You didn’t mention how you wanted to relate it to color though.

Dan

[David Mathis]

Thank you. As far as the color scheme would go I would want the color to be as follows:

At a value of 90 degrees red
At a value of 180 degrees blue
At a value of 270 degrees green
At a value of 360 degrees yellow

I want to the process to start over again after the rotation is greater than 360 degrees, if possible. I can get the the expression to work until it goes past 360 degrees then it stays yellow.

There are two expressions below. One is a slider that and the other is for the color.

Probably something I am overlooking is simple. Thank you again for your response.

For the slider control:

r = transform.rotation
if (r<0) r*-1
else r

This expression will be used to return a positive value even though the rotation is not. This expression will be to create the next expression.

Color expression:
Math.floor(transform.rotation/90)
r = effect("Slider 1")("Slider");
if (r>90 && r<180) [255,0,0,1]
else if (r>180 && r<270) [0,255,0,1]
else if (r>270 && r<360) [0,0,255,1]
else [255,255,0,1]

[Dan Ebberts]

This should work (with positive or negative rotation values):

colors = [[1,0,0,1],[0,0,1,1],[0,1,0,1],[1,1,0,1]]; // red, blue, green, yellow
idx = Math.floor(Math.abs(transform.rotation)/90)%colors.length;
colors[idx]

Dan

[David Mathis]

Thank you! The expression worked but now I have another question. I would like to add a check box to determine if I want it to change color or have the color set to whatever I choose with the box not checked. I tried the expression below but kept getting an error message.

change = effect("Change Color")("Checkbox")'

if (change == true): {
colors = [[1,0,0,1],[0,0,1,1],[0,1,0,1],[1,1,0,1]]; // red, blue, green, yellow
idx = Math.floor(Math.abs(transform.rotation)/90)%colors.length;
colors[idx]
} else {
value }

[Dan Ebberts]

I think there are just a couple of typos. This should work:


change = effect("Change Color")("Checkbox");

if (change){
colors = [[1,0,0,1],[0,0,1,1],[0,1,0,1],[1,1,0,1]]; // red, blue, green, yellow
idx = Math.floor(Math.abs(transform.rotation)/90)%colors.length;
colors[idx]
}else
value


Dan