I am developing a space strategy game with Ogre and I just started to make some 3D models of suns.
My first attempt was to use two spheres (one inside another) to display a sun. The inner sphere represents the surface of the sun and the outer sphere the corona. The suns are emissive, since there are no lights in my scene.
Now I encountered problems with alpha-blending. I read some topics about problems with alpha-blending in this forum, but none of the solutions worked for me.
So, first a picture of how my suns look now:
As you can see, the corona is displayed, but there seems to be a black surface which blots out the sun's surface completely. I don't think that the "black" surface is in fact transparent because you cannot see the orange sun through the red one.
In addition, I'll post my material script:
Code: Select all
material RedSun/Surface
{
receive_shadows off
technique
{
pass
{
ambient 0.0 0.0 0.0
diffuse 0.0 0.0 0.0
specular 0.0 0.0 0.0 0.0
emissive 1.0 1.0 1.0
texture_unit
{
scroll_anim -0.002 0.0
texture RedSun.png
}
}
}
}
material RedSun/Corona
{
receive_shadows off
technique
{
pass
{
ambient 0.0 0.0 0.0
diffuse 0.0 0.0 0.0
specular 0.0 0.0 0.0 0.0
emissive 1.0 1.0 1.0
scene_blend alpha_blend
depth_write off
texture_unit
{
scroll_anim 0.002 0.0
wave_xform scale_y sine 0.0 0.005 0.0 0.4
colour_op alpha_blend
texture RedCorona.png
}
}
}
}
Hm, but I though about that point, too. I have Adobe Photoshop 6 and a plugin for importing and exporting DDS files. Photoshop says that my image contains transparency and I export it to DDS with an alpha channel. So there shouldn't be anything wrong, but in fact, I am not sure. I'll check this out again! 
