Animate Pivot Problem

[iamjaideep80]

Hi Everybody....

Having a problem while animating pivot point (Like in Maya and XSi).

I tried to find it in forum, but got something diffrent.

Let me explain.

Suppose there is a Box geometry,Transform node attached to it.

Everything is default.

I want to Roll the Box on the Ground. How will I do it?

I want to do it Manually, adding Keys to tranform node.

When I animate Pivot parameter on tranform node, It rotates once and then box translates in up and forward. And doesn't remain on the ground.

I think some setup has to be done to do this. But don't know what?

Plz tell me.

Another Question. What is the diffrence between Pivot And Centroid.

I think this concept is very diffrent in Houdini compared to other packages.

In Docs, there is topic, But not explaind.

Can anybody explain it in Detail, with some Examples.

Thanking in advance.

------------iamjaideep80

[edward]

I did a search here and found this:

http://odforce.net/forum/index.php?showtopic=95&hl=

The pivot parameter differs from Maya in that it is the pivot for the translates, rotates, and scales (all at once). I think Maya has separate pivot parameters for rotates and scales. ie. there is no simple "pivot" parameter, but rather there is "rotate pivot" and "scale pivot".

You can think of the centroid as the average point position in your geometry. The pivot is the position about which transforms are applied. The centroid is fixed position that depends on your geometry whereas the pivot is any arbitrary position that you can pick. So you can always make the pivot position be the same as the centroid, but not the other way around.

I think these definitions for centroid and pivot are pretty common in computer graphics textbooks? "pivot" by itself is somewhat ambiguous though unless you say "what" the pivot is for which is where I think your confusion comes from?

[jjstanley]

There was actually a challenge about that a while back. http://odforce.net/forum/index.php?showtopic=95 If you look through the posts you will find several ways of doing it.

[sibarrick]

Of course it's all slightly complicated by the fact you can detach a handle and move it away from the pivot point.... you can still go into pivot mode to move the pivot around but the transforms will be following the handle when you use the handle and the pivot when you change values manually.....