Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: Naxos on 2017-02-16, 22:47:29

Title: Better quality needed in "For compositing" Shadow catcher...
Post by: Naxos on 2017-02-16, 22:47:29
Hello,
I'm trying to get some objects on a pure white support for a customer...
As i know albedo / diffuse would never go above rgb 240-242, i'm using a shadowCatcher material so i can save png rgba files, then photoshop let me put a pure white under it, and i get shadows onto it...

Problem is that the "for compositing" alpha stays grainy, even at 100 passes...

Im using an HDRI for main light, so i can't really raise the subdivisions...

Any help would be usefull, thanks.
Title: Re: Better quality needed in "For compositing" Shadow catcher...
Post by: romullus on 2017-02-16, 22:57:23
I'm affraid currently there's no solution. ShadowCatcher's "for compositing" mode is broken. It is my most anticipated bugfix in Corona - about 80% of my renderings would decrease tenfolds in time if that bug would be fixed...
Title: Re: Better quality needed in "For compositing" Shadow catcher...
Post by: Christa Noel on 2017-02-17, 03:11:59
yes I'm with both of you guys, my eyes are monitoring this problem's progress since long time ago.. but there is still no any answer from devs till now.
my daily works is dealing with tons of design product shot and a fix for this problem will be very helpful.
and in another side, sadly now i realize this dark fact: there are only 3 people from total billions of users need this feature.
Title: Re: Better quality needed in "For compositing" Shadow catcher...
Post by: Lucutus on 2017-02-17, 08:53:08
There are at least four people ;) .

The shadowcatcher really needs improvements asap.

Greetz

Lucutus
Title: Re: Better quality needed in "For compositing" Shadow catcher...
Post by: maru on 2017-02-17, 16:10:27
Hi guys, I have some good news already. I did some tests with 1.5.2 and 1.6 daily build of Corona (it is not yet available publicly) and there is a big difference in image quality. Interestingly, alpha channel quality was even better than beauty. I will be soon back with image examples.

I have also come up with a setup that allows you to set up pure white background, but at the same time have the shadowcatcher material appear black (or anything else) to GI rays. This way you do not need to worry about correct albedo. This involves rayswitch map. I am attaching the .max file.
Title: Re: Better quality needed in "For compositing" Shadow catcher...
Post by: maru on 2017-02-17, 17:54:49
Here are the images you can compare. I am not sharing render times yet, since I am using an assert build, which is painfully slow. ;)
Title: Re: Better quality needed in "For compositing" Shadow catcher...
Post by: Christa Noel on 2017-02-18, 03:03:02
that's a great news!!
now seems the time is coming when romullus remove his "my nemesis" signature.
Title: Re: Better quality needed in "For compositing" Shadow catcher...
Post by: romullus on 2017-03-02, 17:28:59
Maru, can you tell if this fix will be included in 1.6? I tried with Mar 01 build, but didn't see any improvement.
Title: Re: Better quality needed in "For compositing" Shadow catcher...
Post by: maru on 2017-03-09, 16:05:56
Yes, that was made using some standard daily build, which just wasn't yet available back then.
This is the new stratified sampler + lights > enviro sampler. The difference should as well be visible in the most recent dailies, but maybe how visible it is depends on some specific conditions.