Chaos Corona Forum

Chaos Corona for Cinema 4D => [C4D] Bug Reporting => [C4D] Resolved Bugs => Topic started by: dolain on 2018-01-07, 20:49:36

Title: Shadow catcher reflections flipped?
Post by: dolain on 2018-01-07, 20:49:36

Hi,
I might be misunderstanding the point of matte projection mode, but at a first glance the reflection map (in this case same as the backplate image) is flipped vertically - please see the attached print screen. Hope I'm not missing something obvious here.

Best,
Dolain

Edit: Forgot to mention that report refers to Beta 1 RC1.

Title: Re: Shadow catcher reflections flipped?
Post by: dolain on 2018-01-12, 22:21:39

Hello,
I'd greatly appreciate if someone could verify if Shadow Catcher Reflection's matte projection mode works as expected. To me it seems that when we use the backplate as the reflection map (apparently useful for environments with puddles and other non-uniform floor reflections), it's upside down. Please take a look at the print screen below. The reflection map works - brighter portions of the backplate generate stronger reflections, but it's flipped vertically.
It may be me using matte projection mode the wrong way - please correct me if that's the case.
Corona version: Beta 1 RC 2

Best,
Dolain

 

Title: Re: Shadow catcher reflections flipped?
Post by: Eddoron on 2018-01-13, 00:51:20

The catcher's reflection orientation seems fine. I've played with it for half an hour going through all settings.
You might want to try the ray switch shader. You can plugin the shadow catcher into the slots you need and have more control over it.

Title: Re: Shadow catcher reflections flipped?
Post by: dolain on 2018-01-13, 11:58:22

Thank you for looking into this Eddoron, much appreciated!
But have you tried using some texture as a shadow catcher's reflection map? That's where I've seen the problem - assuming that I'd want to create a reflection map based on my backplate, I'd expect it to be positioned and oriented precisely like the backplate, while it clearly was oriented upside down.
I said was because I got it straight now and the solution was embarrassingly simple - changing shadow catcher's texture tag projection to Frontal (previously UVW). I'm not sure why I assumed that ticking "matte projection mode" would do all the work for me... :) So sorry for the false alarm.

Thank you again Eddoron

Best,
Dolain

Title: Re: Shadow catcher reflections flipped?
Post by: houska on 2018-01-15, 13:43:27

What the "matte projection mode" does is simply set the mapping of the Reflection channel to match the mapping of the Shadow channel (look at the smaller caption below the material preview - it says "Matte / Shadow"). So I guess you already found the solution - fix the projection in the texture tag.