Set ramp color position as driven
 

Hi there

I've made an eyeball with a pupil from a ramp texture. Then I've made a custom attribute "Pupil" inside my locator for the eyeball.

Now I want the pupil to crow as the pupil attribute changes. Inside the "Set Driven Key" dialog there is no "position" attribute for the ramp, so I added it inside the "Channel Control" of the ramp, named "colorEntryList[1].position", when I now got back to my "Set Driven Key" dialog I got a new attribute "Position" for the ramp, but when I try to set it as a key, I get the error message "Error: No object matches name ramp1.position".

Am I missing something? Please help me.

Spandy :banghead:

ok, i dnt have a solution, but that is a very good idea!!

you shud link up the ramp position with light intensity, that wud be amazing :)

If I understand you correctly, (and i hope I do), you want basically want to be able to drive where color's position on the ramp will be?

to test I set up a 3 color circle ramp on a nurbs plane. The top color being white(colorEntryList[2]), and the bottom 2 black(colorEntryList[0] & [1]) . The I used the following expression to test it out.

ramp3.colorEntryList[2].position = nurbsPlane1.translateY (replace this with whatever)

as i moved my plane along the Y-axis, the circle grew and contracted, as a pupil would.

Hopefully this was what you meant!

Just tryed it with light intensity, it was pretty cool.

ramp3.colorEntryList[2].position = 1-(ambientLightShape1.intensity)

that would need to be tweaked though

Re: Set ramp color position as driven
 

set driven key does not work for the "colorEntryList[1].position". the attribute "position" does not belong to the ramp either - it is only a virtual name for the selected position when you edit the ramp in attribute editor. if you want to use a sdk then there is a nasty little workaround for it:

• create a new float attribute with the needed min and max values for the position of the the desired colorentrylist in ramp1
• create a new expression with e.g.
  
  Code:

  ---

  ramp1.colorEntryList[1].position = ramp1.pupil_position;
ramp1.colorEntryList[3].position = ramp1.pupil_position-0.02;

  ---

  this you even make as in the example to move 2 positions at once - for a smooth transition from iris to pupil that is always same thickness
• create another attribute (e.g. in the material, not the ramp) form 0 to 1
• create a sdk between the new attribute as driver and the ramp1.pupil_position as driven

hope that helps some

Thanks for your responses.

BabyDuck that was just what I needed.

Spandy