Viewing an object with an alpha texture applied, while that object is in front of another object with an alpha texture applied results in a blending of the two, or the object closest to the camera going totally transparent.
Steps to reproduce:
1. Make a 10x10x10 cube and apply an alpha texture to it.
2. Duplicate the cube and move it 1m behind the first cube.
3. Moving the camera around while focusing on the first cube will cause the first cube to "Blend" with the cube behind it. Worst cases the first cube will disappear similar to the second picture. Picture #1 shows this result.
Picture #1 submitted by ShinIori319 Feichholz - Shows first alpha texture disappearing along the areas with the second alpha texture behind it. The rest of the texture shows up fine.
Picture #2 - Shows the second alpha texture "Blending" with the first one.
VWR-27