[PD] [Gem] changed [ortho] behaviour

cyrille henry ch at chnry.net
Sun Sep 10 23:33:40 CEST 2017


Le 10/09/2017 à 22:34, Roman Haefeli a écrit :

>>> But how can someone use the full window area with the new default
>>> mode?
>> changing the windows perspective!!!
>> (using the perspec message to gemwin, see help file)
> Sorry, I don't understand. Maybe I simply don't understand which
> question this answers.

question : "But how can someone use the full window area with the new default mode?"
answer : "changing the windows perspective!!!"

if you create a 200x100 windows, the perspective is set to 16 unit wide an 8 unit high
you can change that to have 8x8 unit thanks to messages send to gemwin.

>>> Why is there a limit?
>> what limit?
> What I am experiencing when using [ortho] is that only the lower left
> 500x500 pixels of the gemwin can be used for rendering. Also, the
> center seems to be in the middle of this 500x500px area. This is with
> current master (cc0d464a) on Ubuntu 16.04 with a Intel graphics. Please
> check this screen recording:
> http://netpd.org/~roman/ramsch/ortho_limit.mkv

yes, this is a bug with ortho

>> "ortho" change the way object appear smaller far away.
> This I understand. All parallel lines appear parallel in orthographic
> projection.
>>   It also use to change the perspective and was in conflict with the
>> gemwin "perspec" message.
> This I don't understand> 
>> the conflict have been removed.
> I'm a bit confused whether I hit a bug or if there is some big
> misunderstanding on my part. Can you check the above video and tell me
> if you get the same?

i get a problem when the Gem windows is resized.

> BTW: the 'compat' method does not work for me. No matter whether I send
> 'compat 0' or 'compat 1', the rendered output looks exactly the same.
if you render only a rectangle or any flat primitive, then ortho should have no effect.
did you try the help patch, or with a square?

I used a Gem version from few month ago. I don't thik there is any significant change since.

So, all in all :
- if you want a square to be redered as a rectangle (to fit the windows dimention), you have to change the perspective. (see gemwin help / [pd more viewing])
- ortho used to change the perspective, but that was a bug
- ortho does not have any effect on 2d object rendered at Z=0.
- ortho do have a new bug : it's perspective is not affected by a windows resizing, so it consider the windows to be 500x500.

One more thing :
According my memory, I think the perspec message changed :

on a 200x100 windows, for a square to be rendered as a square, you use to send a perspec -2 2 -1 1 1 20 message.
now it's perspec -1 1 -1 1 1 20, so in order to to render the square to the size of the windows, you have to know the window dimension. So in fact, it's easier to change the square size than the perspective...
see attachment


> Roman
> _______________________________________________
> Pd-list at lists.iem.at mailing list
> UNSUBSCRIBE and account-management -> https://lists.puredata.info/listinfo/pd-list
-------------- next part --------------
A non-text attachment was scrubbed...
Name: square_full_window.pd
Type: text/x-puredata
Size: 399 bytes
Desc: not available
URL: <http://lists.puredata.info/pipermail/pd-list/attachments/20170910/4ad24c1d/attachment.bin>

More information about the Pd-list mailing list