Look at constraint

[YOHKOH]

Hi Can some one help please

 

I'm trying to get a lot of planes at different heights to rotate to look at a camera.

 

(Just like in people in sketchup)

 

I set up a dummy and linked it to the camera.

 

Then use look at contraint on my planes to look at the dummy. The problem is the planes will not constrain their rotation to the z axis they also jump around and rotate on other axis to point towards the dummy.

 

It works fine if the dummy is at the same height a a plane but i have an array of them at differeing height.

 

Any ideas??

[Claudio Branch]

First off, you don't really need the link to the dummy. You can assign the look at constraint straight to the camera.

 

After you have done that, you need to go into the Motion Parameters Tab for each object and change the "Select LookAt Axis" to Z and the "Aligned to Upnode Axis" to Z

 

You will probably have to do this for each object individually. Forest Pro does this automatically with large groups of planes and the various Max Particle Systems can do it as well.

[Crazy Homeless Guy]

I use a dummy also. For some reason I have trouble getting Max to lock the tilt axis, so when a camera goes into the air, my planes tilt backwards. So I link to a dummy, then animate that dummy to follow the camera, but stay at ground level.

 

Also, linking to a dummy allows you to quickly point things at another camera if you are creating stills instead of an animation.

 

Haven't tried it with Forest Pro.

[Claudio Branch]

Forest Pro will automatically set the look at constraint to whichever camera is active in the viewport. Very helpful...