0 answers · asked · Lesson: Simulating the Launch Smoke · Course: Build and Animate a Low Poly Rocket in Blender 2.8 for Beginners

the particles suddenly dissappeared under the strand/particle mode

Hi, I have two questions.

The first one is just like the title said, when I change the coordinates into strand/particles, and set the rocket launches at the frame 20, but after 20, all of my particles dissappears; but they are quite fine under the generated mode. 

The second question, when I emit particles, there is always some gap between particles and collision platform, how to solve that problem? thanks a lot!