Edges of transparent PNG


I’ve done a PNG of some reeds to place near a pond I’m modelling. They look good except for a thin highlight all around the edge (the boundary between my reeds and the transparent part of the image.

Is there a preferred way of dealing with this; I guess it’s a fairly common problem. Image smoothing tools/techniques etc? The effect is not noticable in GIMP, only when it renders in Blender.


I have noticed this problem as well. I don’t have a work around as of yet. It is almost as if Blender always assumes the alpha is pre-multiplied instead of straight.


Yeah, I can sort of appreciate why the edges are there - because of the antialiasing making the boundary between the transparent section and the image less clear cut - but it would be nice if there was some way of reducing the effect.

I noticed that in Gimp if you start from a blank image with just an alpha layer and then draw on top of that, it’s not so bad. But unfortunately that’s not much help when working with existing textures.

Hi all,
the .blend from this thread

renders fine for me (2.48, Linux) if I enable “Premul” in the image panel of the texture buttons - does that work for you?

Hey, that seems a lot better actually - thanks!

Thanks MPPIC, I wonder why Blender does not click that button atuomatically by default when it detects an alpha channel present in a loaded image?