How do I unmultiply alpha channel?

Hello, I have a picture that was exported from c4D with redshift. In the picture there is a glow effect (light bulb). the image does included the info for the glow effect, but C3 only displays the alpha as premultiplied I think, so the effect doesn't show up. (see images)

Is there other options for handling alpha information in C3?

thx

Marc.

Premultiplied alpha is an internal detail and you shouldn't need to worry about it at all. Just import normal images (with unpremultiplied alpha) and Construct sorts out whether or not they get premultiplied.

It's not clear from those images that the problem is anything to do with premultiplied alpha anyway. It looks like maybe the effect is made of two images, and you only imported one.

Hi Ashley, thanks for the info, but no, this is an issue with the way the alpha channel is being "layered"

I did the render, so I know it's only 1 image, as you can see in the unlit image, the alpha channel works as intended, no issue there, the glowing effect is an RGB process and not an alpha information. So it needs to be told to sort of Unmultiply the alpha from the image to see the RGB info.

Here is a detailed video from redshift about this:

youtube.com/watch

Thanks.

Marc.