Shadowmatte not rendering reflections

[nikkegrahh]

Hello, when i try to render an image with the shadowmatte and i want to place an object in a photo, i seem to be unable to get the photo to reflect, as i understand it should, according to the documentation. Instead i recive black reflections where the shadowmatte geo is.

I have opaque tuned off for the geo, and the background is made with an imageplan for the camera. I also seem to miss a parameter which exists in the documentation. The background type.

Im using the latest version of arnold but im not sure if im missing something obvious? 🙂 I have read through the latest fixes for the updates but cant seem to find anything.

I also remember bumping into this in arnold 4 but then i had 0 transparaencey depth, which ive checked and is not the case this time.

[nikkegrahh]

I found a way to work around this if anyone would have the same problem. I multiply an inverted alpha of the shadowcatcher with the projected image and plug the color into an aiFlat shader. This give me the correct reflections from the background, catch the shadows and it will also reflect the cast shadows. This is simply to get the right spec and diffuse passes for compositing, with the shadows affecting the geometry. Maybe someone knows how to do this properly, but this is what i came up with!

A tip would be to plug the shadow alpha into a remap node to control it a bit more.