Transparent Surfaces

I really don’t know how to explain this, but when I did VRML, I was able to map a PNG or a Gif with Alpha Transparency and the mesh would disappear and only show the texture. It was real handy when I had to create a gate or a fence, without having to make all the meshes.
Is there a way to do this with blender?


It’s actually really simple but I wrote it out step by step so it might seem long.

Blender 2.49a

If you’re using blender 2.49, go to the Texture buttons tab (F6) in the Buttons window down the bottom and if there is not already a texture created, click add new. For the texture type select image and to the right click load and navigate to your image. Click the UseAlpha button in the Map Image tab which should be in the middle. Once you’ve found it and done select image, go to the material buttons tab (F5) and bring your alpha all the way down to 0 and press the ZTransp button. Now go to the Map To tab somewhere to the right of the screen and click the alpha button. That should be all you need to know.

Blender 2.5
If you’re using blender 2.5, go to the Texture tab in the Properties window on the right and in the drop down menu for Type select ‘Image or Movie’. In the Image tab click Open and navigate to your image and load it. In the Image Sampling section in the same tab, expand it. Check the box next to Use to make it use the alpha. Also in the same tab, go to the Influence section and expand that. Check the Al box (It means alpha). Now go to your Material tab and tick the box next to Transparency and expand it. You can select either Z Transparency or Raytrace. Either is fine (If you need something like glass, go with Raytrace and if you need something like a holographic projection then you could go with Z Transparency). I think it should work now.

I hope it helps.

Edit: If you want the transparency for a fence, Z Transparency would probably be a better option. Raytrace will give you the same result but Z Transparency is faster and is good for fully transparent meshes except for the texture. Raytracing is good for things like glass because it gives better shading in the transparent areas.

I am having a strange problem, Blender 2.5, OSX 10.6.2. What I am trying to do is, I have a model, and I am using texture paint and painting stuff on different images, kind of like using Layers in Photoshop, but Blender does not yet have the ability to work on different images layers like Photoshop. Feature request please! Anyways, so I am using separate images, I’ve got one that’s a base color, one that is paint peels, scratches, stains, and so on. Each one is on its own layer using the same UVMap. Once I am finished, I will bring all the images together as one file as well as use them to generate spec maps and stuff.

Before I flatten all the images to one, I have them added to a material with a bunch of image textures added. Each image has a transparent part as it is meant to be an overlay. Heres the problem the parts of the image that are not fully opaque or fully transparent render what should be transparent and the color underneath as white. For example, if some part of my image was only 50% opaque, and say in front of something that is green, you would expect it to show green in the transparent part, however, unless it’s 0% opaque, it will show white!? I’ve tried this in multiple versions of 2.5, and can’t get it working. Any ideas please?

I also have a few more questions.
How do I create an image that is fully transparent to start?

How do I get Blender to save the alpha channel. When I use add alpha, and erase alpha in texture paint, it will not save these changes to a file. I tried using PNG btw, maybe I need to use a different format to save Blender’s alpha?

Is there anyway to preview multiple textures on an object at once without having to render?

Also, in texture paint mode, when using polygon masking by pressing “M”, is there any way to get blender to highlight the unselected and not highlight what is selected, as that highlight makes it confusing to paint?

Thanks in advance!