You could do a line pick between old vertex position and new one and see if it colided. I think this would be faster than doing a real collision ...
Beside that: A collision system with more than 100 particles would kill your performance which is why you should not do it at all beside a "below ground level" check or "out of view" check which is both already in.
Beside that: A collision system with more than 100 particles would kill your performance which is why you should not do it at all beside a "below ground level" check or "out of view" check which is both already in.