I just want 50 or so groups of objects to sit on the ground (a flat plane). All object groups have flat bases too, but zooming in and tweeking each one at the third decimal place is driving me crazy. Can physics help? Can I use physics to drop everything down to the ground plane, then take their final positions and "start over" as the beginning of future animations and pics? Is there a simple ALIGN function in C4pro? An ALIGN that works from the edge (bottom) of a group and not the center or hotpoint? thanks holly

1. Align from the edit menu (z axis only, have to experiment with the max/min settings to get the correct one) 2) Use collison detection, and pull the objects down manually. 3) Physics will work. . . you'd have to do your start over thing though- maybe just slide up the beginning of animation marker. Would take a while to enable phys. for all the objects. . . Personally, I'd probably do 2. Or you could start over and use Julien's Replica plugin. ;-) Markd

I haven't done it for a while so I'm not totally sure if the option still exists but, You can select the option to move one object until it touches the other. If all your 50 objects are supposed to touch a single plane, you can, 1.) Set all groups at the same elevation (like 10.000). 2.) Group all 50 objects. 3.) Use the align tool to drop the group onto the plane by selecting the contact option. -Kix

Thanks for advice. So I checked collision detection on the plane surface and put it at maximum density and no bounce or friction, but there is no similar option for the groups. The group still simply passes thru the plane. Is there more to it?

Collision detection isn't tied to physics- it shouldn't matter about the materials. You aren't using physics, right? Hmm. Only thing I see is that the "stop" when you strike a plane (as opposed to, say, a cube) is pretty brief under CS4. As you drag down, you'll get a little hitch, you need to stop dragging right there or you'll pull through. Markd

Hi Kixum. All the groups are different heights (it's a city. Each city block is a group. Some blocks have taller building than others). How can I align them all to the same elevation? Where is the align tool? Mark, I am trying to "land" them all on a plane, but maybe I will switch to a wide flat cube and try again...? I didn't notice any hitch, but C4 is starting to be less than responsive with so much geometry.... If I open the group and set the flat bases to "collide", then close the group to move it all at once.... Is that what I'm supposed to do? Never used collision detection and as yet to figure out how to make it work.

It might be slipping by if C4 is feeling stuttery. . I don't do anything to the objects- just go to the view menu, and check Use Collision Detection. Then grab those handy-dandy new manipulators and drag the group down. Should work ok with the group closed (or it did for my simple two-sphere test ;-) The align tool is in the edit menu. Select the stuff you want to align (plane first, then group, otherwise you move the plane to the group). On the align popup, where it says Hotpoint, pull it down and switch to min. Select the Z axis, unselect the y axis, click OK. Markd

The important thing there is that the collision detection has NOTHING to do with the physics panel of the objects. Just by choosing in the view menu 'Collision Detection' objectswill be able to be moved until they contact another object. Since you seem to have built your buildings with a base, then as you drag down the base will hit 1st and stop the building as a whole. Hope this helps!! :D

The top image is a ball and a plane that are clearly not touching. 1.) Selected the plane and then the sphere. The first object you select will not be moved, the second one will. 2.) Selected the align option in the Edit menu. A dialogue box appears. 3.) Selected the options as shown. The result is that the sphere is aligned with the plane and they are touching. -Kix

Yay, long version ;^D