GI in 3D for live action integration

[ethervoid]

Hi, i was just wondering if when you're lighting/rendering some 3D models for integration with a live action plate, using Global Illumination brings any advantage to use Final Gather only, since from every workshop/tutorial i've seen so far on live action and vfx, they only used FG. ( In a typical IBL setting with hdr images providing the lighting). Thank you

[ethervoid]

oh i guess the question didn't make much sense then :x

[anim]

you guessed right

since using mentalray terms on mantra forums may be very misleading

but better understanding of difference between GI and FG even in mentalray may help you understand how those methods rely to mantra which is not so straightforward

usually you just render with PBR with diffuse limit > 0 to get secondary bounces

if you want some optimisation through photon mapping you can use GI light as well, but that can introduce some artefacts so be careful in animations

if you are not using PBR you will need to use GI light in photon or irradiance mode and you may use irradiance cache on mantra as well if you like those FG flickering artefacts

but when learning mantra it's good to forget mentalray and vray workflow and you will feel less constrained

[lukeiamyourfather]

Everything Tomas said. Also Yes, I have used the physically based rendering mode of Mantra a few times for elements that get integrated with live action shots.

http://www.sidefx.com/docs/houdini12.1/rendering/understanding