algorerhythms wrote:Thanks for the comments. For the sky in the landscape image, I'm using a sky_sphere with a bozo color_map. I didn't know about Lightsys. I'll have to take a look at it. I have only one light_source declared in the source file, 6 miles away in the direction of the sun, but I'm pretty sure I had radiosity turned on for that rendering. I've since changed the main .pov file, so I can't be certain, though.
I'm attaching one of the images I generated from the optics lab equipment macros. The only scattering medium in the image is in the vapor cell. I tried to put a scattering medium in the entire room, but POV-Ray had problems rendering it. I let it run for a week, then calculated based on its progress that it would take ten years to complete the image...
The sky_sphere is ok, but you may get better results with a real sphere, although that does have the disadvantage that it can get shadows cast on it, unless its finish is purely ambient with 0 diffuse. However, that doesn't work very well with radiosity, since it tends to be too bright, but it's worth experimenting with.
Using media effectively isn't easy, especially with multiple overlapping media of different types. However, there are some media experts on the POV-Ray forum that can offer guidance in setting media parameters.
A common technique when using radiosity is to do it in two passes. On the first pass you do the render at half the final scale, with all the slow stuff (like media & reflections) turned off and save the radiosity data to a file. On the second pass you do it at full scale, with all the slow stuff turned on, and with these radiosity settings
and for extra speed
There are some examples at Jaime Vives Piqueres' site, eg here
, and I'm sure you'll find more online with a quick search.
Your optical equipment looks very good, but I noticed that you didn't use antialiasing in that render, or if you did the settings are very mild. I can guess why - antialiasing can really slow things down, especially when you're rendering transparent and translucent things like glass or media. One trick I often use is to substitute a little bit of post-process blurring for high resolution POV-Ray antialiasing.
First render your scene at around 20% larger than the size wanted for the final image, with antialiasing settings ranging from
+A0.4 +AM1 +R2
+A0.5 +AM1 +R1
When rendering glass, etc, you may need to drop that to +A0.3 or +A0.2, and you might even like to go up to +R3, although the increased quality may not be worth the increased rendering time.
Once the image is rendered, scale it up by 1.25 to 2.75. Duplicate the enlarged image, blur one copy using a selective Gaussian blur (or similar), mix the blurred and unblurred versions together, and then scale down to the desired size. I usually do the scaling, blurring & mixing using a script of NetPBM commands, or sometimes with ImageMagick, but for more control I do it in The GIMP.