Reflect light...

[Viper0]

Hi, i'm trying to obtain this effect, I post an image to aclarate, but, esencially, I try to obtain illumination inside the box like in real world... I use max 5 and I think need V-RAy too...
Thanks.

[DaftPunk]

You can generate something LIKE reflected caustics through a high intensity bounce in raytracer, or you can use radiosity.

[Mystikos]

Use radiosity. It's fun! I promise...

[finch]

I dont know about whether this will work, but maybe you can try and use the mirror material, but i dont know whether it will reflect the light or not, though I suspect it wont. If you dont want to use refraction and mirrors, or the occlusion thing, then you can use gi, though it might give you too even a light. Try setting up maybe direct spots at the angle that the mirror is supposed to reflect from, and then adjust their falloff. You may need to put some other lights inside the box though to even the light spread out. It will be faster than gi, but may not give the results you are after. Also, from what angle are you going to be showing this? will it be from the mirror? or somewhere where you can see both the lightsource and the inside of the box?

[Viper0]

Thank you for your opinions and sorry for the delay, I left this subject, but the interest that I have in it is great because this is not the effect I want to obtain, is just a simplification of a real word, but I think if I can control this small effect I'll be able to obtain a very realistic world, and especially interiors scenes. In a real world the light is reflected in all surfaces to all directions, and specially in chrome and mirror materials ALL the light, 100 % is reflected specially in the angle that is represented with the drawing. The idea of control this effect is that I make, for example, a chrome object, the light affecting to it be reflected to the near surroundings, creating this characteristic effect that is can be appreciated, for example, in a near wall, as if the mouse behaved like a radiant body of light, 100 % of the light in some cases (with the same intensity), and if I have for example a dark environment, I can create luminosity from an indirect source using mirror effects and similar (like the box idea). I hope the idea is understood, and sorry for my primitive english, I use google translator because not's my native language. :o
Thanks for reading and if anyone have any oppinion I'll be very thankful.

[Thykka]

nope. Absolutely no sense in that. You would have tu use reflective caustics on it and the accurary would have to be really high to project any shadows/accurate GI inside the box. You should just place a directional light behind the mirror, facing the box and exclude the mirror from shadow-casting.

[Viper0]

Thanks Thykka for your reply, but why no sense?? :hmm:
I found a way to make the question easy: Why the mirrors (or chrome, are the same) don't reflect lights??
If I wanted to make this specific scene I'll put a light behind the mirror, but I just want to simulate a simplification of the real effect, but thanks.

[Design]

ViperO , I have found that Radiosity is the best way to give you the global illumination effect. but there is settings and certain type of materials to be used. also it will give you the mirror effect but not as realistic, still it works for me.if your intrested i could tell you how and what.

[Thykka]

Why the mirrors don't reflect lights??
That's the thing I tried to explain but obviously failed :hmm:
Second try:
Suppose you have a flat mirror and a light pointed towards it. It would be relatively easy (for a programmer that is ;) )to program an algorithm that calculates the light bouncing off the mirror. The most common way to do this is caustics. Caustic patterns are usually mady up with photons which are more like samples of light because it'd be very computationally expensive (slow) to calculate each single ray of light bounced. And if you wanted the reflected light rays to cast shadows and not just to illuminate everything on their path you'd need even more calculation time. Now imagine someone would model a sphere with a reflective material and normals flipped and then placed an omni-light in the middle. How many light bounces would that be? Rendering time: infinite.

So if you really want your mirror to reflect light, make sure your renderer supports caustics. The shadow quality won't be quite good though.

[Thykka]

Oh and btw... I'd say the easiest way to do this would be Maxwell Render. Unbiased, Physically (almost) correct and slow as hell.

[Viper0]

Design: thanks for the tip but I try radiosity and I couldn't obtain the effect I want, but thanks anyway ;)
Thykka: thank you for the explanation, now I understand your argument, I know it's imposible to render some scene like you describe, but I search a paremeter to control the "intensity" of this effect. You, and some more people, tell about caustics, do you know if vray support it??
And where can I found a good tutorial to explain it??
Thank you again, and if it not works I'll leave the effect and come back to the fantasy world of 3d Studio Max :D

[DeadlyFreeze]

Theres probably a million ways to do it, heres your setup with mentalray caustics/GI. 8 sec to render...

...and ya Vray supports caustics

[Viper0]

Thanks a lot DeadlyFreeze, this is exactly that I search, the reflection of the light in the mirrors. Finally I obtain the scene as you can see below, I follow the simple tutorial of vray and now I want to found the setting marked on the second image, I try to search it anywhere and I don't found. If anyone can help me... :o Thank you.

[Thykka]

Here's how I'd do it.
This one has area shadows and color bleeding. I suppose both of them are very difficult to attain without cheating.
rendertime 55. sec (16xAA)