Here is my new test on a muzzle flash to be used for real time…as usually,a texture(handpainted),alpha and emitter maps.however there is a little problem.it is lovely renderend with is fake volume(cross planes)but it casts an ugly shadow,the shadow of the planes…i tryed the TraShadow button but nothing works…maybe i am wrong at using two separate textures?one for the color and one for the alpha?
Hi Gaus,
It looks as though your ground plane material is not set to receive transparent shadows, check its material shadow settings. By default, materials are not set to “receive transparent”. If this is not the case, your lightsource may be the cause. A buffered lamp will not allow for transparent shadows, make sure your lamp is set for Ray Shadows.
Hope this helps 
Ben
P.S. for future posts like this, I would post in the Work in Progress forum.
Thanks,i had only to activate the TraShadow on the plane,not on the flash!however,another thing…even if the material has an emitter it doesn’t cast light around the flash and on the ground(maybe because it is rendered in blender internal?)
yeah, you could either enable indirect lighting or just tactically place some point lamps around it 
i ll try,but i think that the unity engine(the one i will use for my game)can read it as a very realistic flash.i will use blender only for testing animations and modelling,but the game itself will be made in unity,however,i am far,an i say FAR,far away from making this game…