Basic setting for caustics effect in C4D

Where: Cinema 4D
Author: poserpro
Created: 1/15/2003
Last Revision: 1/15/2003
Skill Level: Beginner
Viewed 569 times.

this is for beginner's tutorial for setting up caustics in C4D XL 7.*

Caustics in C4D

Doing Caustics in Cinema 4D is fast and easy.

Caustics is everywhere, not only can you see caustics pattern in the bottim of pool, you can instantly view
such natural pheonomen
caustics is not a rendering technique). I try not to explain the technique terms concerning rendering, you
can refer to your manual or
online source. But you migh tlike to know caustics are an effeft of specular light transmission, unlike
radiosity which is an effect of
diffuse reflection.

Take our daily life for example, everyone got jewelery box, the plastic box that keeps your CD, if you
place your jewelery box below
a light source ( sun light, flourscent light, bulb) and on the table ( wood, metal doesn

t matter much),

you will notice a small light
pattern is always reflecting onto the surface of table. For ladies, use your lips stick, cosmetics box, you
can see caistic effects too.
And when in a harbour, caustics are easily visible in day light as they are reflecting on the boat body on
the water, and they are
animating because of the waves. So use everything you can get nearby, like a glass, a POT drink bottle, a
ring ( metal or plastic ), a
tea spoon, even the plastic tail of a pen, just put them under the light source and you will see caustics.

Renderosity Digital Art Community - Tutorials: Basic setting for caustic...

2009-03-18 16:04

http://www.renderosity.com/mod/tutorial/index.php?print=108

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Here I will explain how to set up caustics in C4D ( I am using Cinema 4D XL 7.*, but it is much the same
in the newer R8). I have
written down 2 parts for creating caustics for this tut. One is for a transparent object, the other is for an
opaque one.

Caustics in C4D

First for the transparent object. Set up a simple secne, I use a plane, a sphere, and a light(that all) to start
our caustics journey, and an
interesting one J

Use the Move tool ( E key ) to move the sphere on top of the plane, which is treated like a table face.
Then drag the light above the
sphere preferably a little bit far away.

Here are my settings for the main caustics effect :
For the light :
Doubleclick to open the Light panel.
-General Tab: Leave light Type to Omni, Set Shadow Type to Soft.
-Caustic Tab: Just check the Enable in Surface Caustics. Leave the paras.

For the Sphere :
Add a New Material in Material Manager, Doubleclick it to open the Material Editor:
-Color, checked.
-Transparency, checked. And use BhodiNUT Fresnel as shader, I use gray to white as gradient map for
Fresnel setting.
-Specular, checked.

Now for the most important but simplest part, Render Setting.
Open the Render Setting, in Caustics Item, check Surface Caustics, that

s all.

Do a test rednering. Well can

t see the caustics, what

s wrong, yes I did it on purpose as I like to show

you there is one factor

Renderosity Digital Art Community - Tutorials: Basic setting for caustic...

2009-03-18 16:04

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omitted. So open the Material Editor again, and pay attention to Transparency, you will see a Refraction
at the upper right corner of Material Editor, increase the index value to 1.7 which is about a diamond

s

refraction rate. ( for Refraction values, check P. 505 for
the XL 7 manual ).

Do another test rendering and you will see what you like to learn from this tut.

Caustics in C4D

The second part of this tut is also for caustics, but for an opaque reflective object.
Here I use a Tube Object and assign another material with setting as follows:
-Color, checked. Use gray ( RGB=50-50-50).
-Transparency, unchecked.
-Reflection, checked. 80%. Use dark gray ( RGB=25-25-25).
-Specular, checked. Width and Height both set to 77%.

Use Rotate to turn the ring object to stand on the table in tilt orientation.

For the lighting, I suggest to use Spotlight instead, and add a Target Expression with Ring as the target so
the light is focus on the ring
always.

Now do a test rendering, and you will see the light pattern is reflecting from the ring surface and
noticeable on the table face.

Caustics in C4D

Renderosity Digital Art Community - Tutorials: Basic setting for caustic...

2009-03-18 16:04

http://www.renderosity.com/mod/tutorial/index.php?print=108

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This tut is pretty basic, but it sure help those who wish to learn the useful caustics effects in C4D.

Caustics in C4D

Here is an caustics scene rendered in C4D XL 7.*

Renderosity Digital Art Community - Tutorials: Basic setting for caustic...

2009-03-18 16:04

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Caustics in C4D

A final note :
Try to use different setting, like the Refraction rate in Material, and the Energy & Photons valsues in the
Caustics tab of Light panel.

Caustics in C4D is fun.

Renderosity Digital Art Community - Tutorials: Basic setting for caustic...

2009-03-18 16:04

http://www.renderosity.com/mod/tutorial/index.php?print=108

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