A quick preview of geometry will not be any more efficient without big
complicated geometry (maths side of things) acceleration hardware. OpenGL
and Direct3D require Meshes, and it can take a while to come up with a mesh
for small objects compared to rendering them with low quality flags (we are
talking two light sources - ambient and a directional source, only ambient
and diffuse shading on objects - no shadows - no reflection or refraction).

You can render a high resolution image in under a second. How long will it
take to parse a complex scene into meshes for rendering with OpenGL?

A new version of povray for windows could parse a .pov file when it is
opened, and preview, then as you change the file, look up in a table made
at parse time for what object you are editing, then re-render. A preview
window could even have a text box for clock value, and a drop down for you
to select declared objects names from any open file (eg if you are editing
an inc that calculates rand numbers for transformations, you could have
selected an object declared in another file that uses these random
numbers).

-- 
Tristan Wibberley

(Remove the '.NO_LUNCHEON_MEAT' from my
email address to reply.)


Eugene Lazutkin <eug### [at] carnac-graphicscom> wrote in article
<34b66582.0@news.povray.org>...
| I am talking about preview mode to test geometry, placements, sizes and
| so on (see my original post). I am aware that it is not possible to
recreate
| the exact picture with OpenGL or Direct3D. But we can approximate :-).
| We can simulate complex shapes with basic ones.
| 
| Sometimes I need rather crude picture but I can't use small previews
| because my picture consists of a number of small objects. In this case
| what I need is _raw speed_.
| 
| I know about future convergence between OpenGL and DirectX and I
| welcome it. But they will be distinct at least for 5 more years: first
| commercial version of low-level API is scheduled on Y2K and it will
| need some polish (you can trust me on that :-) ) and don't forget about
| legacy UNIX systems which will support good old OpenGL for their
| lifetime :-).
| 
| Eugene
| 
| Jon S. Berndt wrote in message <34A50D56.A31FDCF9@hal-pc.org>...
| >Eugene Lazutkin wrote:
| >
| >> I agree with you 100%. OpenGL can help a lot when someone debugs a
| >> geometrically complex scene (placements, geometry, sizes) when it is
| >> not practical to use small previews. It may not help to test lights
| >> and
| >> textures but anyway it will be _very_ useful piece of functionality.
| >>
| >> My wish list for future versions of POV-Ray:
| >>
| >> General: OpenGL preview and multiprocessor capabilities.
| >> Windows-specific: (possibly) Direct3D preview, full MMX support.
| >>
| >> Reasons: I see OpenGL and DirectX as the only reasonable way to
| >> support
| >> platform-specific hardware- (and software-) assisted acceleration. All
| >> new
| >> processors are MMX-capable and it is a crime not to use accelerating
| >> facilities for computing power-hungry apps :-). Now when memory prices
| >> are
| >> going down and Intel processors are dirt cheap, it is practical and
| >> inexpensive
| >> to have a dual processor computer under NT or whatever you like. There
| >> is
| >> a number of multiprocessor UNIX computers out there. A lot of people
| >> buy
| >> dual-processor motherboards counting on future upgrades by adding
| >> second
| >> CPU. I believe it should be supported eventually.
| >>
| >> Eugene
| >
| >Note that as far as I know OpenGL has no good way to do CSG - and some
| >other correspondences between OpenGL and POV language do not relate.
| >Also, as for OpenGL and DirectX, Microsoft and SGI have just announced
| >they will work together with their two respective technologies to merge
| >them into a better standard for 3D on the PC. Read their release at
| >microsoft.com or opengl.org or sgi.com. The people I have talked with,
| >and myself, think this is a great move.
| >
| >OpenGL previews would most likely be limited to basic shapes, in my
| >opinion.
| >
| >jon
| >
| 
| 
|

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