[PD] perspective in gem

[Martin Peach]

Miller Puckette wrote:
> I think this comes from the fact that Gem uses a very wide-angle virtual
> lens to look at the model space, the equivalent of a 40-ish mm camera lens.
> I think that parameter is controllable withing openGL but I can't find 
> anything in Gem that allows to change this... 
> 
> simply making the cubes bigger and further away doesn't fix it; you really
> need a narrower camera angle.  Perhaps some Gem expert knows how to set this?

If you make the cubes the same size but further away:

[translateXYZ 0 0 -6.0]
|
[cube]

...and set the perspective so as to view a smaller part of the scene:

[perspec -0.3 0.3 -0.3 0.3 1 100(
|
[gemwin]

...you get the telephoto effect. And you can back off as far as you like 
until you get the lack of perspective you desire, but there is no way to 
have more than one point of view in a gemwin at the same time, except 
for something like using pix_write and pix_image to save individual 
views and then display them together.

Martin

> 
> cheers
> Miller
> 
> 
> On Tue, Jun 14, 2005 at 09:38:14PM -0400, dafydd hughes wrote:
> 
>>Thanks for your reply, Max
>>
>>Max Neupert wrote:
>>
>>>? multiple objects with individual perspective? i'm curious, my 
>>>imagination is limited to my 4 dimensions.
>>
>>I didn't do a very good job of explaining myself.  I've created a 
>>picture of what I'm trying to do:
>>
>>http://www.sideshowmedia.ca/cubes.jpg
>>
>>Basically, each object stays where it is but can be rotated.  Problem 
>>is, as soon as I try to space the cubes out, perspective takes over...
>>
>>
>>>what you might want is to change the shape of your viewpoint or frustum. 
>>>see in the helpfile for [gemwin] the [pd viewing] subpatch.
>>
>>This is a great suggestion - thanks.  I will definitely explore it further.
>>
>>cheers
>>dafydd
>>
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