Mouse Controls to Position Objects in World

[kelly.powers@danahall.org]

- I am using Alice to position an object. I use the mouse control to move a ballerina's front leg forward. The ballerina is facing front.
- this works.

If I turn the ballerina, the entire ballerina, 90 degrees clockwise, then if I use the mouse controls to move her leg forward or backward, this doesn't work as I expected. The leg moves toward the direction, when she was first facing front.

However, if I use the object tree methods, and issue a right leg turn forward or backward, this seems to work in the direction I expect.

Why do I see a difference when using the mouse control? Is this a bug or is this related to the 6 degrees of motion?

[DrJim]

Is this somehow different from your earlier posting -
http://www.alice.org/community/showthread.php?t=1355 ?
If not, see my comments there - if so, please expand on the problem a bit more.

[kelly.powers@danahall.org]

Sorry for re-posting. I read your reply in the first thread that I created. I was hoping that one of the developers would review it to see if this is a bug. I didn't see an option in the forum to move the first thread to the bugs and trouble shooting section so I re-posted the entry to this section. Thanks for your first reply.

[lanceA]

You've obviously discovered a 'feature' in Alice that Mac users have but is unavailable to PC users. You can actually use the mouse on an Object to move it's parts?

Normally I have to use the pop-up menu which allows me to select a method for the object.

Am I missing something?

[DickBaldwin]

You've obviously discovered a 'feature' in Alice that Mac users have but is unavailable to PC users. You can actually use the mouse on an Object to move it's parts?

Normally I have to use the pop-up menu which allows me to select a method for the object.

Am I missing something?

I have been assuming that kelly.powers was referring to the "affect subparts" capability that is explained at the following URLs:

http://www.dickbaldwin.com/alice/Slides/Alice0115cj.htm
http://www.dickbaldwin.com/alice/Alice0115.htm

Is that an incorrect assumption?

Dick Baldwin
Free Alice tutorials: http://www.dickbaldwin.com/tocalice.htm
Free programming tutorials: http://www.dickbaldwin.com/toc.htm

[kelly.powers@danahall.org]

Hi,
LanceA,
I noticed a difference between the methods in the object tree turn forward backward versus the mouse control , move forward and backward. I get different results when I use the mouse control to position an object.

In particular, when I turn a subpart, a leg forward after I face a people object 90 degrees right of facing center, the turn forward mouse control doesn't work as expected.

Please re-read my post to see if you can repeat what I observed. Is this a bug in Alice?

[DickBaldwin]

...

I use the mouse control to position an object.

...the turn forward mouse control doesn't work as expected.



I'm still not certain exactly what you mean when you speak of the mouse control, but if you are speaking of the middle button in the upper right of the Alice user interface (the one labeled Turn Objects Forward and Backwards), I believe that the terms Forward and Backwards in that case are relative to the camera and not relative to the object.

This is a little complicated, because the direction appears to be relative to the camera but the pivot point is the objects center point and not the camera's center point. This is different, for example, from using As Seen by the Camera in a method call.

For example, if you don't check Affect Subparts and then turn the ballerina so that she is facing 90 degrees relative to the camera (she appears to be looking to the right or the left) and then you use the turn button mentioned above to turn her Forward or Backwards, you will actually cause her to roll around her blue axis. In other words, you will actually cause her to turn left or right in the terminology of methods.

On the other hand, when you use one of the methods to turn an object, you are turning it relative to its own red, green, and blue axes and not relative to the camera (assuming that you don't apply the property As Seen By the camera, in which case you get something even different.).

Hope this helps and doesn't simply serve to muddy the waters even more.

I find it very difficult to set a pose using the buttons in the upper right corner of the user interface because the behavior is often not what I expected.

Dick Baldwin
Free Alice tutorials: http://www.dickbaldwin.com/tocalice.htm
Free programming tutorials: http://www.dickbaldwin.com/toc.htm

[DrJim]

I now agree with Dick’s interpretation of the function of the forward/backward rotation button – please disregard my earlier, wrong comment.

If you use the button and mouse to “rotate an object forward/backward” with the mouse, the object turns around it’s pivot point towards or away from the camera (i.e., into or away from the screen). A similar comment applies for the “tumble” button.

A bit strange at first, but if you play with rotating the camera around the object, it becomes a little easier to understand/predict.