Problem with Alpha Textures in GLSL

Game Engine Game Engine Support and Discussion
#1

I am following this tutorial from tutorialsforblender3d.com: http://www.tutorialsforblender3d.com/Game_Engine/WeaponReticle/WeaponReticle_GLSL_Steps_1.html
This tutorial is written for Blender 2.4x, but I am trying to implement it in Blender 2.57b.
The alpha texture does not seem to be working for me. I enabled Face Textures and Face Textures Alpha under Material Options, enabled the Use, Calculate, and Invert Alpha buttons under Image Sampling, but it still won’t work. I have attached the blend file so you can see the problem. alpha_texture.blend (65.3 KB)

If anyone can help me, I would be much obliged.

#2

Hey. I believe the problem is that you need to set the Alpha settings in the material to 0 (with ZTransp), and then, in the Texture for the material, enable the Alpha checkbox. That will make the image show up opaque where you need it, and the end result should be what you want.

#3

Thanks a lot. I sort of have it working. For some reason, it is not behaving consistently. It works on the attached file I provided above, but when I try the same procedure on a different file I have, it does not use the alpha, although I am using the exact same (as far as I am aware) texture settings.

#4

Alpha in the GE is fussy. The settings you need to enable are spread to the four winds. I have no idea why. There are also many ways to achieve alpha transparency.

#5

If you’re using GLSL mode, it’s a different process than using Multitexture mode.

Multi-texture mode:

Simply go into the texture face settings in the Edit mode in the Edit panel, and select Alpha as the draw type. It should at least show up transparent in the transparent parts of the texture, and opaque elsewhere, unless there’s a material assigned. If there is, give it either a blank texture, or disable the texture in the texture face panel, and use the texture in the material.

GLSL mode:

Basically, set the alpha to 0 on the material, go to the texture panel, and set the Alpha checkbox, with the Alpha slider set to 1 - this will enable alpha on the texture.

#6

Don’t you have to enable Z transparency?

#7

I thought I put that in my previous post. Anyway, yeah, enable Z-Transparency in the material.