View Full Version : "visible ray of light bouncing from mirrors" simulation

04 April 2009, 08:28 AM
Hi I am an architect and for an experiment I need to simulate this in 3d max.

like a ray of light coming from a laser pointer and hitting a mirror then bouncing from there to another mirror and goes on like this...

I made the scene using a direct light with added volume light effect. I can create the ray of light effect but it wont bounce from mirrors..

do I need to use a photometric light for it to bounce? I tried it with indirect illumination too but it didnt make any difference...


04 April 2009, 11:04 AM
Why are you trying to do this with light? Why not geometry. That's going to be much, much easier.

04 April 2009, 11:10 AM
Sorry, I just re-read your post and the word "experiment" jumped out at me this time. I assumed you meant it was for a job.

Basically, this is not going to happen. What you're simulating when the light scatters from the volume after bouncing is a caustic, and caustic light paths are tricky, especially when involving multiple specular bounces.

A path tracer like maxwell, fryrender or indigo *might* resolve this, but it will be guaranteed to take a very, very long time.

What exactly are you trying to achieve?

04 April 2009, 12:57 PM
I have to design a building mostly made of glass, which will be semi transparent and will be reflecting around %50 of the light that comes on it, and the shape of the building is a very irregular form basicly looking like a mountain made by crystals (like crytal things you collect in computer games)
this process is essential to me to estimate the light and the heat that will be generated inside the glass cage after the reflections and refractions.

I can guess it already drawing by hand but I wanted to see it like how it would happen in real life

I think to see what I want I need something other than 3ds max? am I right? like a physics motor that simulates these variables? is there a such thing?

04 April 2009, 01:14 PM
I am assuming in my head,
according to quantum theory of light, bouncing is supposed to happen by photon particles, and this is the base of indirect lighting so I am guessing I have to enable indirect lighting and not necessarily GI. I dont know which theorem of light the AQMC renderer uses to generate light but I am guessing it's not photons.. I turn the caustics on but nothing changes... Never used caustics before for renders, do I use it with GI ?

didnt try it with maxwell, I'll try that one today, thanks for the advice

04 April 2009, 01:41 PM
The problem is that you're trying to simulate one of the most difficult-to-calculate light paths there is. You might be able to do it with mental ray and volumetric photons, but you're probably going to need loads of em

04 April 2009, 02:52 PM
this is a physics problem.

i suggest using the services of a qualified finite element analyst, like these guys.

my name's Roger, used to work for Mark.

04 April 2009, 12:47 PM
like a ray of light coming from a laser pointer and hitting a mirror then bouncing from there to another mirror and goes on like this...See if this helps:

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