I searched the help files, the on-line FAQs and found no mention of this.

It seems that collision detection works if you use the mouse to drag your objects or body parts into position, but when I use the parameter dials to position the parts they just pass through each other. (yes, CD is selected on all the parts and their children).

Is this the way collision detection is supposed to work? I prefer to position all the elements with the parameter dials - so was hoping there was some answer for this.

thanks.........

I've noticed the same thing, and no, this isn't how it's supposed to work. It's pretty much useless for my purposes, though somebody might find it worthwhile. If you can see everything well enough to manipulate with the mouse, you can avoid collisions anyway! C-D would be most useful when applying some premade motion, like a pose file, a BVH motion file, or a Python script. In those cases the motion is "blind" and needs to be stopped when it hits an unexpected obstacle. As far as I can tell, there's no Python-level representation of the C-D, so there's no way to make more complicated actions happen.... like bouncing off the target, or moving the target in response to the hit. Those would be easy in Python, if a "report" of the collision were available. But it isn't, and it doesn't work with BVH either.

I realize I'm just learning the new technology for this program ... but I haven't gotten collision detection or cloth dynamics to work yet. I'm a little frustrated, but I understand it's a learning process. Boni

Boni: Here's an example. Set up two Primitive props on screen, like a Box and a Ball so you can tell which is which. Use the mouse to move them apart. Doubleclick on each to get the Parameters and Properties box. Select properties, and in each one check the Collision Detection box. Then click the fourth ball on the upper right of the main document window, and choose Collisions On. After that, use the mouse to move either of the props; you'll see that it stops neatly when it bumps into the other prop. But C-D only works with mouse control, not when you move the object with parameter dials. Also, you can turn on C-D for an entire Figure by the same method: select the Figure and check C-D in its Properties box. Note that C-D only works between objects that have it turned on, so you can leave some objects free to merge.