Magic Music Visuals

Hi, I need to put png-files with alpha onto a canvas. These png-files are elements of a complete picture and they should be able to move etc. around without any impact onto the background. Until now I could not find any option to do so. All the mixoptions in the blend module do something with the background or original colour. It should work exactly like the "normal" mode in photoshop. What do I miss? I thought this should be basic.

And another problem is that as soon as some modules to manipulate colours are involved also a background to these png-files seem to be added and changes its colour. So I cant't change the colour of a yellow brushstroke which originally looks yellow on a black background without altering the complete background to some other colour. Why is this? Is there always a background added even when an alpha channel is there?

Best
Reinhard

If a png image has transparency, it will automatically be layered on top of whatever is below it. You don't need to use any other modules. And the transparency will be preserved even if you use a color module.

Like this:
Does that help?

Hi,
yes it helps. I knew it was basic. Some shaders seem to add something in the background e.g. Auto Color Tone. But this might be a problem of these shaders and not Yor business.
I am happy with that and thanks
Reinhard

Yes, unfortunately the alpha channel is not handled by some shaders. It's best if you use them towards the end of your scene as post-processing effects so that the alpha channel isn't necessary.