Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: Maybejensen on 2022-07-13, 10:15:05

Title: Extremely slow render when using coronashadowcatcher
Post by: Maybejensen on 2022-07-13, 10:15:05

Hey all, I'm currently doing my first "photomatch" job in corona render, previously i used to be a v-ray guy for this sort of stuff.
I find the coronashadowcatcher almost unusable, the rendering times are absolutely atrocious.
-I'm using perspective match on top of a photo to get the persepctive right.
-Then I'm putting the photo into this  material tree and applying to my geometry. https://postimg.cc/Mvd1V2F6
- I made sure to override the direct visibility to black, as mentioned in the shadowcatcher
- The initial render pass takes forever, 10+ min and rendering is then extremely slow
- Corona tonemapcontrol doesn't do much to the rendering time. I've tried bypassing it.

Title: Re: Extremely slow render when using coronashadowcatcher
Post by: Avi on 2022-07-18, 10:02:21

Hi,

Can you please send us your scene and a brief description of your issue in our support ticket here - https://corona-renderer.com/link/contact-support

Once we receive your scene through the ticket, we will investigate the issue and update you accordingly.

Title: Re: Extremely slow render when using coronashadowcatcher
Post by: shortcirkuit on 2023-02-07, 08:42:15

was this resolved?  im also having slow shadowcatcher render times

Title: Re: Extremely slow render when using coronashadowcatcher
Post by: Juraj on 2023-02-07, 13:35:59

It's probably the "compositing mode" For me it was always up to 10times slower than without.

Because it's so slow when I need only white-sweep, I rather use Distance map in opacity Slot of regular white material.
Of course, that doesn't help for true shadow-catcher need like this or automotive.

Title: Re: Extremely slow render when using coronashadowcatcher
Post by: Maybejensen on 2023-02-07, 16:03:53

Quote from: Juraj on 2023-02-07, 13:35:59

It's probably the "compositing mode" For me it was always up to 10times slower than without.

Because it's so slow when I need only white-sweep, I rather use Distance map in opacity Slot of regular white material.
Of course, that doesn't help for true shadow-catcher need like this or automotive.

That's a pretty neat trick. I'll save it for later :)
I ended up modeling on top of the photo, then used projection mapping to get the image to wrap onto the geometry. This way it renders at normal speed and you get all the right reflections and shadows.
Might look a bit funky in the viewport, but it seems to work better for me.