View Full Version : Caustics and Radiosity display indicators

11-24-2003, 07:25 AM
In layout I always wanted some sort of indicator to show where the radiosity and caustics are hitting.
A series of coloured dots would be nice so u can adjust it without having to render.

11-24-2003, 08:39 AM
This is impossible cause Radiosity is the result of awfully complex calculations that can vary from frame to frame and/or from CPU to CPU, unless you dont have problems in waiting for long render times.
The same applies for Caustics.

What you can do, if you have Worley's G2 you can monitor the photonmapping buffer. Too bad LW doesnt provide it for exporting.

Anyhow, since we are on topic, LW-Caustics are a joke for laughs.
Caustics are white and dont carry the color info, not to mention that they need to be more inteligent and work with all aspects of the scene and not only per-light basis.

11-24-2003, 08:44 AM
C4d has the feature to see where radiosity is hitting as well as caustics.

11-24-2003, 09:27 AM
Maybe I misunderstood your request.

To do this interactively, you need one more public buffer, the Global Illumination buffer.
What you want is to subtract from the rendered image the GI-Buffer. Worley managed to do this, but as I wrote before LW cannot export GI as a feature in Buffer-Export-View/Render.

My initial point is, that in order to have this result available, you have to render first. Before rendering is impossible to see where radiosity will appear. Sorry for misunderstanding ;)

11-24-2003, 11:51 PM
I wondered how did I got confused with your request.

Its due to the word indicators on the topic.
I interpret it as "not 100% accurate" or "aproximation"

Actually Radiosity is applied on "all" pixels if your sampling is detailed enough. If it is not enough you will get a lot of sharp noise, which can be smoothed with Shadow Noise Reduction.

Think that # of light rays are infinite and Radiosity tries to interpret them using finite means. This results in noise due to undersampling. (MonteCarlo is a statistical Term)

LW's Radiosity and Caustics appear ONLY to the areas that are exposed to Light. In order to get the second bounce either cheat with Ambient Light, or prepared for long render times.

So, what you ask can have two answers, depending on your requirements. Radiosity with limited undersampling is applied on the majority of pixels. Caustics usually show up at the neighbouring surfaces of Reflective/Refractive objects.

A monitoring / visual indication of these effects ...
as I wrote before, the most possible is using Worley's G2.

11-25-2003, 09:40 PM
mental ray has that option.

11-26-2003, 10:45 AM
EyesClosed... MentalRay also has an option to make Coffe, Tea or Capuccino out of your own LAN cable!


12-01-2003, 01:18 AM
and caustics are not responding without lights..... s.....s