The idea was simple. Get an image of a tree, with alpha, stick it to a plane, hey presto 2D tree. Cram a few trees onto the same spot facing different directions and you have a passable 3D tree.
There are a few obvious options that would achieve this. First up:
Texture > Influence > Alpha (1.0)
This seemed to receive some alpha info from the image, but the rest of the plane remained black, and the fuzzy halo around the edges was not actually transparent anyway. Hmmm. Several off-topic or out-dated tutorials later, I just started bashing at the UI again. Maybe all the settings I need are not in Texture?
Then I found the crucial material setting:
Material > Transparency (check) > Z-Transparency, Alpha 0.0
At Alpha 1.0, nothing happens. But at alpha 0.0, the whole material is by default transparent. This works in conjunction with the Texture influence setting, so that the alpha of the non-transparent parts of the texture will raise the alpha level above zero. Its sort of backwards, making everything transparent and then filling in the visible tree parts, but perhaps this is just my strange way of doing it.
Even after I did this, though, there was still the annoying halo. I recognised this as the parts of the image with an alpha between 0 and 255, where it was fading in/out. But why was it not working? Luckily, thanks to listening to JP in cinematics last year, I had some idea that this effect is linked to something called 'pre-mult'. Having seen this word in the texture options before, I found it and checked it.
Texture > Image > Premultiply
I expected more options surrounding the premult, like in After Effects or Premiere, but there was just the check box. Praise be to the Corn God, it worked.
I added back in Brayden's trunk (I made my own planes since something was seriously weird with the UVs on his ones, possiblyOBJ conversion related) which I textured with bark, and erased the trunk from the source image to finish off the tree.
You would think 4 planes would be better than 2, but somehow I like the version with just 2 better. Perhaps it's the angle of my render camera.
