POV-Ray : Newsgroups : povray.advanced-users : lemon {} revisited : Re: lemon {} revisited Server Time
14 Apr 2024 19:54:25 EDT (-0400)
  Re: lemon {} revisited  
From: William F Pokorny
Date: 12 Mar 2023 11:41:52
Message: <640df2c0$1@news.povray.org>
On 3/12/23 08:45, Bald Eagle wrote:
> IIRC, it was the single-image photogrammetry where I had an issue with all my
> stuff disappearing because it hadn't damned on me how LARGE the objects were,
> and therefore how far back they extended (past the camera plane).   So yeah,
> it's WAAAAAY back.   I'll try to keep those under-the-hood issues about the
> solver and the camera distance in mind.

With the orthographic camera, the distance doesn't matter with respect 
to the size of scene things. The size of the orthographic camera plane / 
rectangle does matter - and that the plane be back a small distance from 
all the objects and bounding in the scene.

The location of the camera's ray shooting plane can be very close to 
objects. The orthographic camera rays are more difficult for the 
solvers, as a rule we should position the orthographic cameras close to 
the objects in the scene.

My (-z / looking toward +z) orthographic camera code is:

//---
#declare VarOrthoMult =
5.0/max(image_width/image_height,image_height/image_width);
#declare Camera01z = camera {
     orthographic
     location <0,0,-2>
     direction z
     right VarOrthoMult*x*max(1,image_width/image_height)
     up VarOrthoMult*y*max(1,image_height/image_width)
}
//---

To see a larger part of the x/y plane in the scene, I change that 5.0 
multiplier to something larger.

---

The spindle modes of the regular torus were added to v3.8 and have now 
existed some years (4-5 give or take?), the f_torus modes came with the
addition of functions, the isosurface object and the function vm - which 
I think goes back to v3.5. Those working in v3.7 would have only the 
f_torus spindle options available. The lemon too isn't there in v3.7 
being new in v3.8.

Bill P.


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