Billboard particles

[Rapture]

The Light Rays are billboards, use the Billboard Icon on the left side of the Level Editor. When you open up the Explorer, go to the "billboard" path and find the one you want.

The dust are Particle Systems, you can find the Particle System Icon on the left side of the Level Editor and browse through the particle folders.

"So, that it starts with initals velocity from some position and ends after a few seconds ?"
If your looking into custom particles for your needs, play around with the Particle Editor.

HPL3 Wiki Start Guide - https://wiki.frictionalgames.com/hpl3/to...icleeditor