The randomizer that creates particles on geometry shapes can also use volumes (ex. boxes) and 3d parametric geometries in general.
New randomizer for particle velocities for ChEmitter. This new velocity randomizer ChRandomParticleVelocityAnyDirection creates velocities of random direction and random modulus (the modulus can have a statistical distribution of ChDistribution class)
New demo 'demo_emit_cluster', demonstrating emission of random shapes inside a cube geometry, and funny animation of gravitational effect between particles.