Forum Moderators: not2easy
The most often named free ray tracer is POV [povray.org]. If you need more realistic (physically based) quality, then Radiance [radsite.lbl.gov] is the tool of choice (also free, binaries for Windows, sources unix only at the moment). There are a number of free modelling programs out there, many of which can produce data for both renderers, such as Blender [blender.org], Octree [octree.de], Moray [stmuc.com] (for POV), or even Intellicad [intellicad.org] (an Autocad clone).
Depending on the quality of output you need (or don't need), there may be many much simpler and integrated packages out there. I'm primarily familiar with the high-end stuff myself, which means that I could help you best if you really need absolutely perfect results.
You didn't say what type of models you need to visualize. Any more specific requirements you might want to share?
I do need quality results and I really could be rendering anything (though nothing massively complex). I currently need it to generate some simple geometric shapes for use in some big icons I need - however I expect I'll need to push it a bit harder in the future.
I guess I'm looking for a balance between ease-of-use, fun and quality results but I'm not willing to pay tens of thousands!
Am I right in guessing that some of the free/shareware solutions can take sometime to get 'familiar' with?
Thanks for any further pointers.
(PS - No worries lorax, I just wasn't a hundred percent sure)