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Re: 3d device coordinates from a 3D polyline.... [message #81502 is a reply to message #81501]

Mon, 01 October 2012 10:07

George.millward
Messages: 26
Registered: October 2012

Junior Member

On Monday, October 1, 2012 6:32:00 AM UTC-6, David Fanning wrote:
> George.millward@yahoo.com writes:
>
>
>
>> I have am idlgrpolyline which I can rotate in a 3D view (with the trackball).
>
>> I want to know the 2D coordinates of this line in the device (ie,the 2D the projection in the window). Can't figure it out.
>
>
>
> I'm no expert in this area, but I think the 3D to 2D
>
> conversions of the transformation matrix (which you
>
> can recover from the trackball) are well known. You
>
> can read the answer at the bottom of this article,
>
> for example:
>
>
>
> http://math.stackexchange.com/questions/336/why-are-3d-
>
> transformation-matrices-4x4-instead-of-3x3
>
>
>
> Cheers,
>
>
>
> David
>
>
>
>
>
> --
>
> David Fanning, Ph.D.
>
> Fanning Software Consulting, Inc.
>
> Coyote's Guide to IDL Programming: http://www.idlcoyote.com/
>
> Sepore ma de ni thui. ("Perhaps thou speakest truth.")

Hmm,

So there is nothing in the object graphics system like the 'CONVERT_COORD' routine ?

George.

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[Message index]

		Re: 3d device coordinates from a 3D polyline.... By: DavidF[1] on Mon, 01 October 2012 10:10
		Re: 3d device coordinates from a 3D polyline.... By: George.millward on Mon, 01 October 2012 10:07
		Re: 3d device coordinates from a 3D polyline.... By: David Fanning on Mon, 01 October 2012 05:31
		Re: 3d device coordinates from a 3D polyline.... By: George.millward on Fri, 28 September 2012 14:31
		Re: 3d device coordinates from a 3D polyline.... By: lecacheux.alain on Tue, 02 October 2012 02:22

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