Is there a piece of software (or maybe a renderer that I can use with Blender) that will allow me to accurately simulate the interaction of light with objects?
I am trying to visualize the light beam as it passes through various lenses or reflects off mirrors. What is the easiest way to do this?
Blender supports this internally. It’s called raytracing.
Or do you mean so you can visually see the light, like a laser in fog? I think Povray does it, but I don’t know.
POV Ray is good for stuff like this as it is physically accurate (well, most raytracers are, just some more than others). Of course you could always do it manually with Blender and guestimate:p.
It’s not free, but Maxwell is exactly what you are after. www.maxwellrender.com. Search these forums, someone has used their blender models with Maxwell…
POVRAY does do it, however. And quite well. One of the sample files that comes with the Windows version is exactly what you want.
Try indigo. It’s free!
I simulated a camera with it a while ago, it works very well. It’s like maxwell.
Ian
optics.pov is the sample file that comes with POV-RAY. It shows laser light being dispersed through lenses and mirrors, and it shows the light as though in a light fog, though you don’t see the fog.
I appreciate the replies. I’ve had family come visit me over the past week and haven’t been able to visit to forums.
I already know about the POV-RAY file. Blender is my strength though. I know almost nothing about POV-RAY and I don’t have the time to learn it right now.
I thought about Indigo, but I wasn’t sure how to do it. What kind of settings would I use to make the light rays visible?
I was intending to use such and experiment on light in a classroom setting. Thus, it needs to be as accurate as possible.
I thought about Indigo, but I wasn’t sure how to do it. What kind of settings would I use to make the light rays visible?
Well, it’s designed to be physically accurate and can’t do volumetrics, so you can’t directly see the rays.
You can, however, set up a ray box like you would in reality:
http://indigorenderer.com/gallery/main.php?g2_itemId=155
Great idea…didn’t think of that. 
Alltaken: I’ve never heard of WinOSi. I’m looking into it right now. What is meant by “slow?” Is it as slow as Indigo?
Are both of the renderers compatible with the latest Blender?
(just out of curiosity, how does yafray .9 compare in terms of realism?)
I don’t know of comparisons between indigo & winosi, though I think indigo is quicker. Both will give you very accurate results. So will radiance http://radsite.lbl.gov/radiance/
However, I never got that one running.
Are both of the renderers compatible with the latest Blender?
WinOsi I tihnk has an exporter, but I’m not sure. Indigo does, and it is in active development. Have a look in the forum, leope does the exporter.
By slow i mean a cornell box will be 200+ hours if you have enough objects in it.
the thing is it will give you Every light effect spot on accurately (you can’t turn them off infact)
caustics, and shadows are unavoidable parts of the design, you can’t render in it without them. lights need to have a form they don’t exist simply as a point in space, they exist as only an object (sphere or plane or whatever)
also effects like correct spectrum splitting (over the entire range, not just rgb splitting), and the effect where colours go blurry around the edge when looking through a lens co of their different refractive indexes…
The renderer is super damn spot on… if you have weeks to wait for each render.
it renders from the Phototon (not photon mapping or aproximation, it does every single photon), and renders starting from the light source, and not from the camera, hence all its results are correct.
if i were the coder of the software, i would design it to remember the data from multiple camera angles at once, since it would be no extra rendering time to do so. (perhaps it could, i dunno, maybe thats a feature request)
Alltaken
Are you talking about dispersion and seperating the visual spectrum as it passes through a prism:
http://en.wikipedia.org/wiki/Prism_(optics)?
nope, i am talking about colouring in rainbows with crayons, it splits the spectrum perfectly 
na i am talking about that Dittohead, its just i am a noob when it comes to thinking of these big words.
Alltaken
and the effect where colours go blurry around the edge when looking through a lens co of their different refractive indexes…
Chromatic abberation, I think. Same as dispersion, but when in a lens taking a picture (or in your eye, look at a bright light and see [or be blinded])
Jaycun (and anybody else curious about it):
thanks to the link provided by Alltaken, I’ve looked around in the galley and found a page with a picture of a scene with a list of links to shows comparison of different rendering by different softwares of the same scenes.
just click on the name of programs u wanna see the scene rendered by and the page will loads that pictures.
http://www.winosi.onlinehome.de/Gallery_t14_01.htm
Sorry, I was replying to the original thread, I never even read your last reply
Waaaaah Waaaaaah :’( stop making such hurtfull comments.
i’m telling Ztonzy on you.
Wow! More replies.
IanC: I’ve never had much luck with Radience either. Never got it running.
Alltaken: Yeah…ummm…200+ hours is a little too long for the type of stuff I am intending. My parents went crazy with a 68hr render time…I rather not risk a 200hr render time (and summer is already hot enough w/o the CPU 
)
Dittohead: Yes…dispersion and absorption. I want to be able to replicate most of the well-known optical phenomena (caustics, dispersion, absorption, polarization, total internal reflection, etc.) I recently looked at a list of features for Yafray and I discovered that most of these can be simulated with Yafray (hence the question of yafray .9 above). I want it to be as accurate as possible b/c it might be used in a classroom setting (don’t want obviously faked results, the effects need to be accurate enough to point to and explain as something that would happen in real life).
the WinOSi renders do look very pretty though!