General
The window is divided into three sections: file handling, preview, and editing.
The top section (file handling) allows you to import particle systems from PS files. PS files are used by Natural-Selection to hold the particle systems used in-game. You may want to look at your ns/ns.ps file for some examples. It also allows you to export the currently loaded particle system to a PS file or a Valve Hammer Editor 2.2+ map file. Finally, you can also copy the particle system to the clipboard a plain text.
The centre of the window is taken up by the preview area. This is where you see the results of your editing. You can drag using the left mouse button to rotate the view, drag with the right mouse button to zoom, or shift+drag wit the left mouse button to translate.
The lower part of the window is devoted to the editing controls. Each tab controls one aspect of the particle system.
Main
This tab is controls the display of the particle system in the editor.
Show ground: Displays a flat plane from (-100, -100, 0) to (100, 100, 0). You an select a texture for this plane by using the File->Load ground texture... option.
Show grid: Displays a point every 10 units.
Path to ns directory: This is the directory sprites are loaded from. It is saved between program runs in the file nspsedit.cfg.
Create particle system: This starts a new system running. You must press this to see the results of any changes you make!
System Parameters
This tab controls options that affect the system as a whole.
System name: This is the name that uniquely identifies the system. You can't use spaces here.
Max particles: The maximum number of particles that will be "alive" at any one time.
System lifetime: How long the system will create particles. Use -1 for "infinite".
Particle lifetime: How long each particle lives. Use -1 for "infinite".
Generation rate: How many particles will be created every second.
Particle Appearance
This tab controls the look of the particles.
Sprite: Which sprite to use. If you use the ">" button to choose a sprite, make sure to convert the filename to a relative path!
Sprite format: Information on the type of the sprite.
Sprite frames: The number of frames the sprite has.
Animation speed: The speed of the animation (frames-per-second).
Particle size: The starting size of the particle.
Maximum scaling: If the particle has a non-negative lifetime, it will scale itself over it's lifetime to end up size*scale units across.
Base colour: The colour of the sprite. Usually set to "255 255 255" to allow the sprite to control the colour.
Maximum alpha: The opacity of the sprite.
Render mode: The "style" of the sprite. Natural-Selection only support Additive rendering; other types may give unexpected results.
Particle Generation
This tab controls the generation of particles.
Generation shape: This controls the shape of the volume in which particle are created. Valid values are Point, Box, Sphere, Blob. When one is selected, an explanation of the parameters appears to the right.
Params: The effects of these are specific to each generation shape. Refer to the online text for details.
Particle Velocity
This tab controls the velocity of newly created particles.
Velocity shape: This controls the meaning of the velocity parameters. Valid values are Point, Box, Sphere, Box2. When one is selected, an explanation of the parameters appears to the right.
Params: The effects of these are specific to each velocity shape. Refer to the online text for details.
Spawnflags
This tab controls "on/off" options.
Start on: This only affects particle systems intended for use in env_particles_custom entities. When checked, the system does not need to be triggered to start.
Particle density: When checked, the "generation rate" is per 1,000,000 cubic units.
Fade in: Fades particles in over their lifetime.
Fade out: Fades particles out over their lifetime. Both fade flags can be checked at the same time.
Use gravity: Particles are affected by the world gravity setting.
Use tris: Draws particles using triangles rather than quads. Provides a small speedup in exchange for graphical quality.
Minimize edges: I don't think this works in NS. Not implemented in any case.
Constrain pitch: Prevents particles from rotating themselves on the verticle axis. Useful for rain effects.
Collide: Has no effect in the editor, but cause NS to remove the particle when it collides with world geometry.
High detail: Has no effect in the editor, but tells clients they don't have to draw this effect in-game.
Face up: Orients the particle to face upwards (scanner sweep effect).