Converting grey layer to transparent

[lcetina]

I have a light grey layer containing shadow (Question-Start.png) exported from a 3D application. I can use it over a background layer using a Multiply blending mode. But I would like to convert it to a transparent layer without losing any shadow information, like the example in the attachment (Question-wanted_result.png). Any ideas on how to do that?

[Mylenium]

Convert the values to a layer mask using Image --> Calculations or similar operations that involve saving a selection like directly copy&pasting in the data after converting to greyscale and isolating the mask channel.

Mylenium

[lcetina]

Thank you for your reply. Could you please explain a bit further 🙂

[c.pfaffenbichler · Accepted solution]

• Put the Layer (or Smart Object) in a Group

• Change the Group’s Blend if-settings as indicated in the screenshot, splitting the white This Layer-handle by alt-dragging it 

• put the Group in another Group and apply a black Color Overlay to that Group

[c.pfaffenbichler]

Another option is using a Blend if-setting and a black Color Overlay on two Groups. 

[lcetina]

Thank you. As a result I need a .png file with transparency as in the example I attached in the first post.

I tried this technique but didn't achieve transparency within the shadow, only in light grey background. Maybe I did something wrong in Color Overlay?

[lcetina]

Thank you very much! 🙂