ok, time to write down couple more links.
as mentioned before there are many rendering engines available on the market. free and commercial. this entry is about rendering engines in general, not necessarily with blender support (most of them however can render your .blend scenes this way or another). i will write them down without any order, except maybe i’ll start off with the one that brought to me the idea of indirect lighting in cg.
it was brazil for 3dsmax and it was quite a while ago, when computing scene’s lighting was extreme task for pc’s of that time. it was in my opinion the best renderer that could be used for high quality renders with 3dsmax for a very long time, but i started to understand there’s something more out there when i tried…
…vray. with good understanding the way vray works you can get really nice and clean renders with pretty short render times. process of creation accelerated even more when chaosgroup introduced vrayRT, which was milestone in production pipeline. there is a project that integrates vray with blender and it works pretty well even with recent blender builds.
since im writing about engines i’ve used with 3dsmax i should mention mentalray, which biggest upside for me was it was bundled with max. there’s also another product to be found on their webpage – iray. never tried it, so i can’t comment it in any way, but renders look great.
anyway, when i tried vray i understood that area of render engines is evolving, so i started to check other software. even earlier i had checked indigo, when it was still free, but back then render times were ridiculous on my machine, so i gave it up even if i knew there is potential in it. that’s the main flaw of unbiased engines (not as painful as it used to be though, since more and more renderers use gpu’s in computation). indigo also has RT introduced lately and developers make sure many applications can export to indigo format, so it became an interesting option.
when it’s about real-time rendering you have to mention blender’s cycles. still in early development, but there are already cycles builds available.
however it still lacks many important features, so when using blender it’s good idea to check other engines which are free, like yafaray for example. yafaray resembles vray a bit in scene management and just like vray you can get really nice and pretty fast renders when you get to know it. yafaray integrates with blender perfectly. and even if it lacks some material features (like displacement for example, which you can always use directly on high poly meshes instead) it’s really amazing piece of software.
just like another free render – luxrender. unbiased, but gaining speed thanks to gpu utilization in recent versions. and again, the integration with blender is great, you can even access online material database from within blender gui and download them directly into your models.
another free unbiased renderer is nox, new product from evermotion. it has useable exporter (and material importer) for blender. it is in early development stage and still lacks features, but has growing material database and is really worth keeping eye on.
one more renderer, which i haven’t checked myself yet, but should be included here is mitsuba, which is using both biased and unbiased methods in rendering process, to balance speed and physical correctness.
now, learning and comparing all those renderers would take some time, so it might be good idea to read this thread covering the subject to some degree.
i should mention other projects like povray or aqsis for example. or even more (even if it seems these are halted or officially closed): kerkythea, sunflow, toxic.
of course there are also great commercial renderers: (octane, maxwell, finalrender, fryrender, thearender, bunkspeed,etc.), most of them have trials available and are closely connected with other software, but you can find exporters for blender as well.
to close the subject, there is partly obsolete, but comprehensive summary of rendering software here.