Disco Ball - How to ?

[Adam H. Stewart]

I have just been working on a project creating a Diamond material with nice Caustics, Reflection and Refraction. I couldn't get light patterns I was happy with due to the unusual design of the gem. Then last week I was in a nightclub in New York and I thought - damn that is the effect I want.

Three different colored lights hitting a disco ball - and all the light reflections travelling around the floor at different speeds. So how do I create that in 3D using Vray. I have tried making a mirror ball and hitting with a Vray light, with caustics but I don't get the sharp lighting effect I am after. I know the trick of creating a bunch of spotlights and reloving them but that doesn't really create the same feeling.

Am I missing out on simple trick ?
The secret to the disco ball that was lost in the 70's ?


Thanks for your suggestions & help.

[flipside]

I think you will not be able to recreate that effect with caustics... Usually caustics are used close to the object that casts them (for example a ring, a glass, etc...) The settings are also adapted to this. You can control how far vray should look for any caustics etc... So if you wanna do a disco ball hanging 2 meters above the ground, you'll need damn accurate caustic settings, which will make it impossible for animation.

edit: ignore all the above, my assumptions were wrong! Also the search dist setting for caustics has nothing to do with how far the object is from the caustics, as I first thought.

[Da_elf]

for a disco ball i would use an omni with the texture of moving points as a projection map excluding the ball itself

[flipside]

I'm doing a test with photon mapped caustics and it works surprisingly well!

[flipside]

Here's a small test:

http://www.aversis.be/disco.avi

I used a geosphere without the smooth option as a discoball, with a 100% reflective vray material.

Spotlights are max spotlights without any decay. In the vraylight properties you need to set caustics multiplier to 10000 or something (very high - only if you use no decay). I used caustics subdivs = 750.

Settings in the caustics rollout are almost default (except for multiplier). I played a bit with the settings but the defaults were pretty good. Lower the search dist for sharper caustics.

Is this what you mean?

[percydaman]

nice job flipside

[Adam H. Stewart]

Great

That looks really great - I think it was the Spot light with decay that was killing my effect. This is really excellent.

Thanks a million again.

I can hear that crazy 70's drum beat - Travolta is on his way over.

[Dynedain]

for a disco ball i would use an omni with the texture of moving points as a projection map excluding the ball itself

I did that once for a chandalier (no gi involved) in a huge space and it worked very well.

[Gijs]

that looks excellent flipside!

[Morbid Angel]

yeah good work, I will post mine tomorrow :P

[Morbid Angel]

here is the disco ball i made...all tho I didnt take the caustics approach, I tried the true way of calculating indirect caustics but had no success. So I tried maxwell. And yet again I failed :P

[flipside]

I also tried gi caustics first...

Did you use a glossy mirror material on the disco ball?

[flipside]

I think my example worked well because I used std max spotlights, without decay. In reality you also need a well focussed beam of light if you want to have sharp reflections of light on the floor.

[Morbid Angel]

yeah i got glossy metal mat on it.

[Adam H. Stewart]

Interesting

Now what is very interesting, the surface reflections for Morbid's Disco Ball look spot on. With the first example the hits on the ground looked great but the surface of the ball looked unrealistic.
I think a hybrid approach has to be the way to go.