Using trans function

[BIGAL]

I need some help, I am working on something I need to use trans. 1st up it all works in Bricscad but not in Autocad.

 

Within a layout I am getting a point from modelspace but need its co-ordinates in paperspace, so drawing line work. I have a viewport with rotated view, via viewport get its center point world co-ords then use (trans pt 0 3) to work out point in pspace. 

 

To test just getpoint in a model space view, then use trans should return correct co-ords, I am sure its something simple maybe a variable not set.

 

This is rough test by eye in Bricscad actual program is correct linework.

Mspace

(setq pt (getpoint))
(248.0 121.0 0.0)
: (trans pt 0 3)
(114.671115898589 91.2742053827904 0.0)

: ._PSPACE
: id  Select point to identify coordinates: 
 X=114  Y=90  Z=0

 

Can not provide all code as unsure of copyright at this stage.

 

(setq  cen (vlax-get obj  'Center ))
(setq ht (vlax-get obj 'Height))
(setq wid  (vlax-get obj 'Width))
(setq sc (vlax-get obj 'customscale ))
(setq ang (vlax-get obj 'TwistAngle))
(command "._MSPACE")
(setq vc (getvar "VIEWCTR"))
(command "._PSPACE")
(trans vc 0 3)

the issue seems to be with Autocad and view center

Command: _.MSPACE
Command: (setq vc (getvar "VIEWCTR"))
(811.989 -184.058 0.0)
Command: (*Cancel*
Command: _.PSPACE
Command: (trans vc 0 3)
(811.989 -184.058 0.0)

this should be like 400 300
 

Edited August 7, 2020 by BIGAL

[dlanorh]

(trans pt "from" "to") IIRC you can only use trans ("to" = 3) with ("from" = 2) so perhaps (trans vc 2 3) and/or (setq vc (trans (getvar 'viewctr) 0 2)). Not really my strong point so can't be any more helpful.

[marko_ribar]

Not sure, but from my experience, I think you should use trans in the way it converts WCS to DCS and then DCS to PCS... I think I saw this somewhere from Gilles (gile)... It goes something like this : (trans (trans pt 0 2) 2 3)

Not sure for all this but try it...

HTH.

[BIGAL]

Thank for responding. The task was do a grid in pspace the model is a rotated view grid reflects real world co-ordinates.

 

I did get it to work used. (setq psnewcen (trans (trans newcen 1 2) 2 3)) and reverse (setq  startw (trans (trans start 3 2) 2 1)), the issue is you must be in the correct space Mspace in the viewport. It was interesting Bricscad just worked with 0 3.

 

I will amend the code as I will remove the need for the pspace to model, trans as I was retrieving a X or Y so can use a + X spacing.