This isn't necessarily an animation specific question, but it came up in the context
of an animation, so I 
figured I'd post it here. Is there anyway to rotate a point? In case that's not clear:
I know I can rotate a 
point by saying:
	#declare POINT = <1,4,5>
	#declare POINT = POINT + <clock, clock*2, clock*3>
or something like that. Is there any way to do a similar thing with rotation?
Thank you.

Reuven Weiser

P.S. In case you're interested in the specific context and can come up with an
alternate solution - I'm making 
an animation of a juggler. I first modeled the flight and pattern of the (7) balls. I
then modeled the hands 
and forearms to follow the balls. This involved translation and rotation. Now I need
to do the upper arms (as 
cones) keeping one point as the shoulder and transforming/rotating the other end to
attach it to the end of 
the forearm, forming the elbow. If you can think of anything, please let me know.
Thanks.

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Reuven Weiser schrieb in Nachricht <369### [at] aolcom>...
>This isn't necessarily an animation specific question, but it came up in
the context of an animation, so I
>figured I'd post it here. Is there anyway to rotate a point? In case that's
not clear: I know I can rotate a
>point by saying:
> #declare POINT = <1,4,5>
> #declare POINT = POINT + <clock, clock*2, clock*3>
>or something like that. Is there any way to do a similar thing with
rotation?
>Thank you.
>
>Reuven Weiser


I may be missing your point completely, but have you ever heard of the
functions in POV-Ray? There are two vector functions, called vrotate and
vaxis_rotate. These seem to do what you want. Or do you mean something
completely different?

--
Rudy Velthuis

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The clock variable can be used anywhere a number can be used, so you can rotate
clock*y with no difficulty.

You might want to look into a more generalized animation technique similar to my
AniMaker file.
(http://www.spiritone.com/~english/animaker/animationbasics.html)
If the clock goes from 0 to 1 you can use the following:

#declare Start = <1,4,5>;
#declare End = <2,6,8>;

#declare Position = Start + clock * (End - Start);

This can be adapted for scaling and rotation as well.

Josh English
eng### [at] spiritonecom

Reuven Weiser wrote:

> This isn't necessarily an animation specific question, but it came up in the context
of an animation, so I
> figured I'd post it here. Is there anyway to rotate a point? In case that's not
clear: I know I can rotate a
> point by saying:
>         #declare POINT = <1,4,5>
>         #declare POINT = POINT + <clock, clock*2, clock*3>
> or something like that. Is there any way to do a similar thing with rotation?
> Thank you.
>
> Reuven Weiser
>
> P.S. In case you're interested in the specific context and can come up with an
alternate solution - I'm making
> an animation of a juggler. I first modeled the flight and pattern of the (7) balls.
I then modeled the hands
> and forearms to follow the balls. This involved translation and rotation. Now I need
to do the upper arms (as
> cones) keeping one point as the shoulder and transforming/rotating the other end to
attach it to the end of
> the forearm, forming the elbow. If you can think of anything, please let me know.
Thanks.

Post a reply to this message

Rudy Velthuis wrote:

> I may be missing your point completely, but have you ever heard of the
> functions in POV-Ray? There are two vector functions, called vrotate and
> vaxis_rotate. These seem to do what you want. Or do you mean something
> completely different?
>
> --
> Rudy Velthuis

    vrotate is exactly what I was looking for. Thank you very much. (I am
somewhat familiar with some of the POV-Ray functions, but had somehow managed to
miss the vector functions.)

Reuven Weiser

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