global photon

[proces2]

this has probably been answered already (if so, please direct me to the appropriate thread). but, can someone provide an explanation as to the difference between rendering with an irrad. map vs. using a global photon map.

i read in a recent thread that the global photon map is scene (not image) dependent, so wouldn't that be the best thing to use for an animation. but, all the tips and tutorials say to use an incremental irrad. map.

just curious.

thanks.
sean

[R2J2]

global photons are used during secondary bounces, ther's a check box to store with irradiance map and they can only be used with VRay Mat'ls

[proces2]

so what qualities does it add to the irrad. map when global photons are used? is it just for caustics?

sean

[egz]

Global photons are not used for caustics, and may also be used in the first bounce instead of the irradiance map.

I suggest you work through Vlado's Global Photon tutorial:
http://www.vrayrender.com/stuff/PMapTutorial/

[proces2]

thanks. that tutorial will definitely help me start to understand how it all works.