Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: BSimon on 2021-08-08, 21:11:59

Title: Long time exposure with rotating HDRI night sky
Post by: BSimon on 2021-08-08, 21:11:59

Hi, I would like to make long time exposure night render with HDRI night star sky by rotating  hdri map + set long time exposure on camera setting. Do you have any idea how to animate HDRI rotation? (I would like to get this bautiful effect of lines of each star in the sky).
I`ve tried to animate HDR rotation with HDRI map offset settings but for some reason it doesnt work..

BR,
Szymon

Title: Re: Long time exposure with rotating HDRI night sky
Post by: BSimon on 2021-08-08, 21:59:28

I mean something like this:
(file in attachement)

Title: Re: Long time exposure with rotating HDRI night sky
Post by: romullus on 2021-08-08, 22:43:49

Animating HDRI rotation should work, just don't forget that you also need to enable motion blur, but honestly, i would simply replace the background image with sky that has already star trails in it and wouldn't bother to do this in 3D. From perspective of observer on earth, stars are indistinguishable from 2D projection, you won't gain anything by rendering their motion in 3D, but you will have to pay a performance penalty.

Title: Re: Long time exposure with rotating HDRI night sky
Post by: BSimon on 2021-08-08, 23:20:35

Thanks romullus!
I always prefer rendering above photoshop but honestly in this particular cas maybe it is better do do it in this way you said.
BR,Szymon