Is there any way to make the Arnold Shadow Matte act like the Mental Ray Matte, Shadow, & Reflection?

[nievesmiranda0630]

We've been using Arnold and experimenting for a while, trying to imitate our previous renders in order to stay consistent with our previous outputs (S-1) but, of course, there are still differences that can't be helped. Anyway, we tried using the Shadow Matte for the flooring of our projects. It looks ok when you see it in the render window (S-2).

(S-1)

(S-2)

In the render window, you don't see the shadows that are received by the Shadow Matte Map but when you save it (S-3), you'll see that there are subtle shadows found at the corners of the booth.

(S-3)

In our previous set-up in Mental Ray, we usually just put one light, a daylight in CIE mode, and a shadow/matte/reflection plane. In the shadow/matte/reflection plane, we turn off the receive shadows option so we can only see the reflections. We didn't touch the Exposure Control settings for our CIE renders. In the new Shadow Matte Map, there's no option whether you can receive shadows or reflections unlike in its Mental Ray counterpart so I'm wondering if there's anyway to remove the shadow and only leave the reflection and vice-versa. We save our renders in PNG format in order to be more flexible with our final backgrounds.

Below are the settings I used for the Arnold renders (S-3 and S-2).

I hope you guys can help. Thanks!

[lee_griggs]

Does the same issue happen in the Shadow Matte AOVs?

Have you tried using the Ray Switch shader?

Which file format are you saving out to?

[nievesmiranda0630]

Hi! We haven't tried the AOVs yet since we just started using Arnold. We're using a really basic setup. We're not familiar with the Ray Switch shader either. We save our renders in PNG format in order to retain the transparency and to be more flexible with the backgrounds.

[lee_griggs]

Is it the same with EXR?

You could also try disabling some of the General Properties for the floor plane and/or stand geo to see if that gets rid of it.

How are you lighting the scene, with the environment lighting? Maybe a skydome would give more controllable results? Lights have a Contribution that can also be tweaked.

[madsd · Accepted solution]

Hello, not saying this is the perfect solution for you.
But, I made a video that shows how to pick your lights out and reflections in the alpha of the render.
Hope it helps in some way.
https://www.dropbox.com/s/u89xv57arvx91ef/2019-10-07%2012-09-43.mp4?dl=0

[nievesmiranda0630]

Hello!

@Lee Griggs I haven't tried EXR yet but I'll see it first then I'll get back to you. Thank you!

@Mads Drøschler Thank you for this! Will check it out and let you know the results. Thank you!

[nievesmiranda0630]

Mads Drøschler I tried your tutorial and it gave me the outcome I wanted. Please see the render below:

I would just like to ask how to make the reflections more visible. When I try to increase the specular intensity, the reflection begins to glow. Is there any way to make the reflection similar to the reflection of the one rendered in Mental Ray (see below)?

Once again, thank you for your tutorial!

[lee_griggs]

You could also tweak the Specular IOR and add Coating to change the reflection.

[nievesmiranda0630]

My experience in raising he IOR usually ends up with a glowy reflection, almost as if its lighted. I couldn't find a way to coat the Shadow Matte material (I used the map to material utility for this). Also, one thing I noticed is that when saved as a JPEG file, the reflection of the object has the same colors as the actual object (see below).

However, when saving it as a PNG in order to have a transparent background, the colors of the reflection are the inverse of the colors of the object (see below).

If the background is white, this happens but if it is colored, it's normal.

[lee_griggs]

Ah ok, I thought you were using Standard Surface. Coating is only available there. Did you try EXR or TIF instead of PNG?

[nievesmiranda0630]

Hi! Saving it as TIFF makes if similar to a JPEG, i.e. there is a background. I haven't tried EXR but I would like to stick to PNG. Thanks!