Pandafox wrote:I tried to make a special particle with no rotation at all but I can't find how to do.
When particle appears, it always apply some random rotation. Did I miss something ?
I don't think you have done anything wrong.
As far as I have tested this, the behavior you observe is correct.
It seems that the particle always have a random rotation when spawned, even when you specifically indicate 0 for the rotation parameter.
With the fact that the particles are always facing the camera that two limits I know of for the current particle system. For example we can't apply animated particle texture to an horizontal plane since the particle will be drawn vertically.
I do not know if this can be upgraded or changed by the devs easily, but it could be nice to have a more advanced system where there is no rotation in the texture when you do not want it and where you can apply the particle effect on a surface not aligned with the camera facing.