Center Point

**Center Point -** 09-10-2010, 04:19 PM

Is there a way to change the center point of a model? I want to make my spaceship roll, but the horizontal line is on the very bottom, so the roll isn't right. I was wondering if I could move the line to the middle of the model. Is that possible?

debussybunny563 · **It'll take effort. -** 09-10-2010, 06:16 PM

Yes, but you'll need to download some 3-D editing programs like Blender, and it'll definitely take some work.
I'm not sure if it's worth it for just an off-center centerpoint, as there are simple workarounds.

If x2495iiii comes on later, he can give a better explanation/a tutorial.

x2495iiii · 09-10-2010, 09:38 PM

Inside Alice, you can use the alternative method of using another object as a pivot. Insert a geometric shape, like a cone or bump, then move it so that it's center is at the center of the spaceship. Now, set the spaceship's vehicle to the shape, and you can have the shape turn and roll, making the ship turn along the shape's center point instead of its own.

09-11-2010, 06:36 AM

Good solution. So simple I thought it would be a "snap" to implement. Can you look at the attached and let me know why the "do together" does not run. When you disable the "turn forward" the ball and monkey travel forward.

The ball is big and striped so I can see what is going on.

debussybunny563 · 09-11-2010, 08:18 AM

That's because you're making the ball move forward AND turn forward at the same time. Since the ball moves forward relative to itself, and it's turning, the ball constantly is changing direction, resulting in the circular motion you see.

I assume that you want it to be like the monkey is rolling forward, and to do that simply change the ball turning forward to the monkey turn forward. And, since the monkey's pivot is off-center, click on "more" next to the turn forward and choose "asseenby=beachball"

Ex.
<monkey> setvehicle to <beachball> (just for future reference, if you go to the properties tab of an object, you can set the vehicle right there without having to put in in a method)
Do Together
<monkey> turn forward <4> revolutions; duration=<4> seconds; asSeenby <beachball>
<beachball> move forward <4> meters; duration=<4> seconds

I also attached the world:

SlithyToves · 09-13-2010, 08:44 PM

I am having this same problem with a Lego man I imported into Alice, but I am trying to make the person's leg turn, eventually to make him walk. The leg is a subpart and I am not sure how I would implement this workaround in a subpart:

Quote:

Originally Posted by x2495iiii

Inside Alice, you can use the alternative method of using another object as a pivot. Insert a geometric shape, like a cone or bump, then move it so that it's center is at the center of the spaceship. Now, set the spaceship's vehicle to the shape, and you can have the shape turn and roll, making the ship turn along the shape's center point instead of its own.

See the attached world.

x2495iiii · 09-13-2010, 10:37 PM

You'd make the dummy object vehicled to whatever the subpart was vehicled to, then make the subpart vehicled to the dummy object.

SlithyToves · 09-13-2010, 10:48 PM

Thanks for your help. Should I put the dummy object at the place where I want the leg's pivot point to be?

x2495iiii · 09-13-2010, 10:50 PM

Yes, and be sure to orient it properly as well so that turning and rolling it works properly.

SlithyToves · 09-13-2010, 10:55 PM

What is the proper position? (I assume you mean the dummy object.)
Thank you again!