Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: 3Dsoldier on 2018-12-03, 10:50:33

Title: Udh cache with light color animation?
Post by: 3Dsoldier on 2018-12-03, 10:50:33
Hello,
I am going to render an interior animation where camera is animated and light are animated in color. Some are Corona lights and some are Corona light material.
I read already that if the lights are animated translated, rotated etc. then the Udh cache will not work, but what's happen if lights change in color only? Or in Color and Intensity? Is the Udh cache good for that kind of rendering?
Title: Re: Udh cache with light color animation?
Post by: FrostKiwi on 2018-12-03, 17:57:19
Hello,
I am going to render an interior animation where camera is animated and light are animated in color. Some are Corona lights and some are Corona light material.
I read already that if the lights are animated translated, rotated etc. then the Udh cache will not work, but what's happen if lights change in color only? Or in Color and Intensity? Is the Udh cache good for that kind of rendering?
What you properly read was about rendering UHD cache once and applying it to the time-line (or a range of frames), aka "V-Ray's flythrough mode", where you calculate GI only once to get a huge speedbump in rendering the animation.
By default there is no issue in using UHD cache with colored or moving lights, as it recalculates on each frame.

Unless you specifically changed that behavior, you need not to worry, it works just as you would expect by default.
Title: Re: Udh cache with light color animation?
Post by: maru on 2018-12-10, 17:53:56
If you save only one UHD Cache file and re-use it for all frames, you should not animate your objects or lights (including light color), because the UHD Cache file will be still "frozen" and will not reflect those changes.
If you calculate UHD Cache from scratch for all frames, it will work fine even with animated lights.

Also, this is a perfect case for using LightMix. Set up LightMix, render your animation with no animated light color, then compose LightMix in post production software (e.g. After Effects), and animate the color/intensity of your light there. That would work fine even with just a single UHD Cache file re-used for all frames.