I'm new to Blender and trying to make an image. I'm almost there but something is confusing me. Right now, I have this blue rectangle that I want in the same plane as the other objects. For example, here it is from a couple angles:
Now, I want that blue rectangle to be mostly transparent, so you can see the rest of the shape that it coincides with very clearly. So, I went to the materials tab with that object selected, clicked the transparency box, and messed with the alpha parameter, making it very low:
Now, when I render it, it does look different...but isn't actually transparent:
what am I missing here? How can I achieve this?