[Steve_Yorkshire]

I always thought that the stock fizzle fade looked a bit like venetian blinds opening across one plane - so I added another plane!

At the bottom of shaders/common/torque.hlsl:

/// Called from the visibility feature to do screen
/// door transparency for fading of objects.
void fizzle(float2 vpos, float visibility)
{
   // NOTE: The magic values below are what give us
   // the nice even pattern during the fizzle.
   //
   // These values can be changed to get different
   // patterns... some better than others.
   //
   // Horizontal Blinds - { vpos.x, 0.916, vpos.y, 0 }
   // Vertical Lines - { vpos.x, 12.9898, vpos.y, 78.233 }
   //
   // I'm sure there are many more patterns here to
   // discover for different effects.
   
   //yorks old fizzle out
   //float2x2 m = { vpos.x, 0.916, vpos.y, 0.350 };
   //clip( visibility - frac( determinant( m ) ) );
   
   //yorks new fizzle in
    float2x2 m = { vpos.x, 0.916, vpos.y, 0.350 };
    float2x2 n = { vpos.x, 0.350, vpos.y, 0.916 };
    clip( visibility - frac( determinant( m ) ) );
    clip( visibility - frac( determinant( n ) ) );
}
 
 
#endif // _TORQUE_HLSL_

All this does is make it fizzle on both x and y planes equally. And remember, translucent materials do proper alpha fading without this fizzle effect.
Fizzle on dudes!

[Steve_Yorkshire]

Obviously this is dx only (I've not done any messing around with openGL) so if someone else wants to fiddle with shaders/common/gl/torque.glsl feel free to knock yourself out. Having a quick look it has some comments about creating patterns.

/// Called from the visibility feature to do screen
/// door transparency for fading of objects.
void fizzle(vec2 vpos, float visibility)
{
   // NOTE: The magic values below are what give us 
   // the nice even pattern during the fizzle.
   //
   // These values can be changed to get different 
   // patterns... some better than others.
   //
   // Horizontal Blinds - { vpos.x, 0.916, vpos.y, 0 }
   // Vertical Lines - { vpos.x, 12.9898, vpos.y, 78.233 }
   //
   // I'm sure there are many more patterns here to 
   // discover for different effects.
   
   mat2x2 m = mat2x2( vpos.x, vpos.y, 0.916, 0.350 );
   if( (visibility - fract( determinant( m ) )) < 0 ) //if(a < 0) discard;
      discard;
}
#endif //TORQUE_PIXEL_SHADER

[Duion]

It is not the end of the file for me, are you running an older version?
Better say directly what to replace and not just "at the bottom"

Hm I tried it out and something has changed on the fading, but hard to tell if it is better or not. Would need some direct comparisons.