-- Caustics -- Back to tutorial index

Overview: Dictionary.com defines this as: The enveloping surface formed by light rays reflecting or refracting from a curved surface, especially one with spherical aberration. Basically I will show you in Cinema how to make an object refract light, with lights. It is a very nice effect and can add a lot to a completed image.

WARNING: Caustics CAN be render intensive, if you are going to implement caustics in a large image, be prepared to wait.

Step 1: Its all in the settings! First you need to have a scene set up, for the example its just a sphere on a plane. First things first: The sphere should have a transparent matierial, the light needs to shine through right? and secondly, the matierial that the caustics display on should have a little reflectivity and be opauqe (solid).

Here is an example without caustics. Its just a green sphere on a plane...now we will get to the interesting part.

Step 2: First we need to edit our render settings like this: make sure that "Surface Caustics" is checked.

Step 3: Now we will create a light source, as caustics cant happen without one =) In the example i have created a round spotlight.

Step 4: Now we will edit the caustic settings for the light source. In XL7 double click the light in the object manager and find the caustics tab, in R8 click the light once and change the attributes in the ...attribute manager. In the example I put the energy level at 500% and the photons at 150000

Thats really all there is to it! You will yield different reults by different shapes, matierials, light placement, light values, caustic energy levels and photon levels...that part will have to come with experimentation.

Here is a shot with the energy level the same at 500 but photon levels at 3000

And another with a different matierial, a square spotlight, caustic energy at 1500% and photons at 75000. As you can see, there is almost limitless varieties of effects!

Questions? Mail me.