2010-11-07

is there povray lang without rendering?

On Nov 7, 5:48 am, namekuseijin wrote:
> On 6 nov, 13:50, Xah Lee wrote:
> > i think povray was geek love about 15 years ago. I think it's dead
> > since mid 2000s.
> > In the 1990s or perhaps 1980s, it used to be that every self-
> > respecting coder would know about POV-Ray. Today, i don't think most
> > “hackers” know what it is. But they probably have heard of Blender and
> > Gimp for sure.
>
> yes, but you can't "code" in those with the same ease as with pov's
> SDL.

i've been wondering about that. Specifically, for my needs, i really need a lang like povray that lets me program (say in python) to generate the povray sphere box lighting etc positions and sizes, to generate a picture. Usually for math illustration purposes.

• 〈Illustrating Geometry with POV-Ray〉
http://xahlee.org/3d/illus_geometry.html

however, for my need i don't really need realism rendering alone with its waiting for the picture.

also, i really want real-time viewing and animation than static images. (see http://xahlee.org/3d/viz.html )

so, in past few years, i've been somewhat looking. Am pretty sure these days Blender or perhaps others has scripting that that really does what i need much better that POV-Ray. That is, a language that describe geometry primitives that can be rendered, but i don't really need fancy rendering like ray-tracing, but more or less just projection and dynamic interaction....

for example, let's say i have a sphere of radius 1 at position {2,3,4} and a box of side length 1 ot {2.5,2, 2}. Then, suppose my camera (view point) is at {-1,3,2} looking in the direction of origin.

all i want, is to have this rendered into a image. But i don't need realistic rendering. I rather have instantaneous rendering even with just outline, and say once it's created in blender, i can rotate or change view point in real time.

is this possible with blender?

for example, here's POV-Ray rendering:

http://xahlee.org/SpecialPlaneCurves_dir/ConicSections_dir/ball_shadow.png

showing some properties of conics. Really nice. But often all i need are these:

http://xahlee.org/3d/i2/conicsHypCut3D.png
http://xahlee.org/surface/helicoid-catenoid/helicoid-catenoid_twist4.png
http://xahlee.org/MathGraphicsGallery_dir/sphere_projection/sphere_proj_illus.png
http://xahlee.org/PageTwo_dir/MathPrograms_dir/scr/curved_space_mac.jpg
http://xahlee.org/MathGraphicsGallery_dir/SpheresCubes_dir/spheresCubes.html

i tried to learn blender but it's quite complex.

btw, i HAVE spent many hours reading about Blender. I know it has scripting lang (it uses python) and i know it even have a game engine built in (meaning: real-time animation and physics engine even, particle systems etc. But i think the project is still much beta and no doc).

My question is, those who blender experience, whether blender could practically be used like POV-Ray since i don't really need POV-Ray's rendering but need all the blender's interactivity etc features.

Xah

 It's the difference between having a DSL and having a general-
> purpose language with lib calls.  Makes quite a difference, specially
> for stuff like this:
>
> http://local.wasp.uwa.edu.au/~pbourke/exhibition/scc4/final/
>
> its newsgroups still is very much alive though, specially off-topic.


On Nov 8, 11:49 am, namekuseijin wrote:
> On 8 nov, 17:02, Xah Lee wrote:
>
> > Xah wrote:
> > > bpy.ops.mesh.primitive_uv_sphere_add(segments=32, rings=16, size=1,
> > > view_align=False, enter_editmode=False, location=(-1.35352, -2.99709,
> > > 0), rotation=(0, 0, 0), layer=(True, False, False, False, False,
> > > False, False, False, False, False, False, False, False, False, False,
> > > False, False, False, False, False))
>
> > but i was really hoping in Blender too... given its status, i think
> > it's trivial to create a primitive descriptive lang similar to POV-
> > Ray, and my guess is that it's already there...
>
> Its language is python and all it does is access Blender API.  In
> other words:  it's merely a general-purpose language calling libs and
> it does suck for that task.  Pov's SDL OTOH is a DSL for 3D scenes and
> a very good one at that.  It's particularly best for math
> visualization indeed.  It's isosurface primitive can describe general
> functions.
>
> > the best i've done is a cube. lol.
>
> but that's the default scene! :p
>
> > btw, do you know how to in POV-Ray to make the rendering outline only?
>
> there are some very tricky tricks to do that, like this:
>
> http://tuabiht.chez-alice.fr/PovEdge_Site/faq.html
>
> but it's not very feasible because that's not how povray works:  there
> are no "edges" so to speak in povray primitives because they're not
> polygon meshes, they are indeed geometrical primitives described by
> math equations.  Raytracers simply intersect light rays in the scene
> with the surface of such geometric objects.
>
> still, you may try it.

http://tuabiht.chez-alice.fr/PovEdge_Site/PovEdge.html

that's useful info! exactly what i needed. Too bad POV-Ray can't do it.

about Blender not able to take a scene description file for creating simple geometric objects, i'm still not sure. There's also the .obj file, and recently collada file format, and vrml, and possibly there's import utility that takes pov files. So, it's likely one can just use python to create objects in these files. Also, besides Blender, there's quite a few other free 3D modelers... am sure one of them can do it.

... also, Second Life is about to support importing mesh using collada format.

am sure that for someone working in this area... there's easy route to create 3D scenes by using python or any lang to generate a file of highlevel dsecription 3d primitives similar to pov's format, then just run a program so that the file gets important into any of the interactive 3d package, thus then can be viewed and manipulated in real time.

Xah

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