View Full Version : question on follow or maybe expressions

03-22-2009, 11:17 PM

I have a question for you...

Here is my example picture:


see the "pivot" is show in GREEN, and the windshield wiper is shown in RED. if i rotate the GREEN pivot I want the RED wiper to move "down" so to remain contact with the glass.

Using modifier "follower," If I rotate GREEN pivot 30 degrees I can get RED wiper to rotate down 2 degrees, but if I move pivot -30 degrees, the wiper actually rotates "up" away from the glass.

I'd like the wiper to rotate "down" 2 degrees toward the glass if the pivot is in either 30 or -30 degree rotations.

Any suggestions?

03-23-2009, 04:34 AM
Try to see if the expression will work with an abs (absolute) function strategically placed.
In this way, the resolver always sees a positive number and stays attached to the glass.

03-23-2009, 01:18 PM
Another thing that might work is to render out the depth buffer of the glass and use that to displace the wiper so that it always maintains contact.

03-23-2009, 01:49 PM
I like splinegods idea...

but I think a few points, softfx, and dponts node motion applied to bones to make them follow the points would work better.

This method would also work with splinegods idea too, but you would displace the points instead of using softfx.

I just think the soft fx would be easier to set up...

03-23-2009, 02:14 PM
Also, you could add a gradient on top of the displacement map so you can tune how much the wiper is displaced.