Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: britbunkley on 2023-05-19, 10:57:00

Title: animate a camera using an HDRI background w/o slipping
Post by: britbunkley on 2023-05-19, 10:57:00
Can one animate a camera using an HDRI background without the foreground objects slipping? I've attached my settings and a clip of it slipping.
Title: Re: animate a camera using an HDRI background w/o slipping
Post by: romullus on 2023-05-19, 11:08:52
You can use Corona bitmap with dome projection mode.
Title: Re: animate a camera using an HDRI background w/o slipping
Post by: maru on 2023-05-19, 14:01:07
Yes, as Romullus said, you can use Dome mapping for this:
- an older Max tutorial - https://youtu.be/1cZ7k6BJd30 (https://youtu.be/1cZ7k6BJd30)
- a newer C4D tutorial - https://youtu.be/0q4f9ydj6tA (https://youtu.be/0q4f9ydj6tA)

- Chaos Docs - https://docs.chaos.com/display/CRMAX/Corona+Bitmap#CoronaBitmap-DomeMode

Alternatively, you could render your backplate without the objects and then use some sort of tracking software (possible with After Effects, PFTrack, definitely many other apps, probably Blender). But that might be an overkill, especially if you are able to get away with dome mapping.
Title: Re: animate a camera using an HDRI background w/o slipping
Post by: britbunkley on 2023-05-20, 07:13:05
Thanks! This mostly works, so far, but it is very tricky to limit the dome distortion with the radius and camera height. I can't seem to get rid of it 100%, but it is very close at these settings... Now to try and get that hair sorted (using black in the slot still has it come out as brown).
Title: Re: animate a camera using an HDRI background w/o slipping
Post by: Juraj on 2023-05-20, 13:23:04
That's why this sort of camera mapping is better done with actual geometry, like chamfered half-dome, or even one that maps the sphere into more exact shape, in this case a rectangular room.

But it will always look like trick, this will never work 100perc :- )