Alpha images

I want to use planes textured with tree images in the background as a low res solution to a rural landscape. Unfortunatly when I manage to make the none tree parts of the image transparent it shows only the background. Obviously I’m making an alpha map in my final render but thats not what I wanted to do.

How do I make a texture transparent in places so that it shows other objects through it?

Well first of all you have to make sure that your images are in a format that supports alpha channels, for instance, Targa, PNG, TIFF…
JPEG does not use an alpha channel.

And in the texture buttons where you load the image, click the button that says “Use Alpha”.

Once you have the alpha set, you need to enable Ztransp as well.

I can put an alpha channel on an image. Its getting it used by Blender I’m having problems with. I’ll try the tip. Thanks for replying.

I was just about to post this as a thread, but I suppose this is a very similar problem.

Suppose I want to obtain the effect of a glazing with spraypaint on it,that is, the surface must be transparent everywhere but the “spraypaint” drawing on it must be opaque and have a certain colour. How do I achieve that?I tried messing around with maps, alpha channels and stuff but I’m just trying in vain.I know there are renderers out there that make use of “transparency” or “opacity” maps.What is the Blender equivalent for it?

This has always bugged me but I realise that the transparency problem was with the source file as I use Corel Photopaint and Ive found out what I was doing wrong when saving the tga

Thats fine now but how come the shadow cast is still the size of the plane rather than the transparency - is this just unavoidable?



It always seems to be the way when I ask a question, moments later I find the answer…

I wasnt settining trashad (trace shadow)? on the material that was recieving the shadow…

works great now, but seems wierd that its set on the target rather than ‘from’ the object casting the shadow. Strikes me this would be a pain in animation because all objects in a scene would need to be set this way (unless you knew exactly where the shadow would be cast…)


As you can see in the tutorial, obviously not. But you need raytraced shadows, and make sure “TraShadow” is switched on for the material receiving the shadow.