particle systems using and creating copyright © 2015 curt hill
TRANSCRIPT
Particle Systems
Using and Creating
Copyright © 2015 Curt Hill
Introduction
• Particle systems are way to add inconsequential movement and realism to a level
• There are several that come with UDK
• You may also create your own• Like SpeedTree gives you the
option to inject realism easily
Copyright © 2015 Curt Hill
A Particle
• A simplified actor that moves within a level for a limited time
• There are two pieces:– An emitter– A particle
• These typically do not interact with the players that much
Copyright © 2015 Curt Hill
The Particle
• Polygon mesh, although usually very simple
• Each particle has: – A starting position – determined by the
emitter– A lifetime – usually measured in
seconds– A characteristic trajectory
• It is spawned, it moves and then disappears
Copyright © 2015 Curt Hill
Mesh• Most actors have a complicated
mesh with suitable material covering– Typical tree is thousands of polygons
• The quad particle is most common– A single four sided polygon
• A card
– It is covered with a material
• More complicated meshes are allowed but are often not needed
Copyright © 2015 Curt Hill
Lifetime
• The emitter spawns the particles• The lifetime is the duration in
seconds in which they exist• A rain drop might exist for five
seconds• A bug may exist for considerable
longer
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Distribution
• The particle never comes to rest• The distribution describes its
position and scale over time• Raindrops and bugs do not change
in their lifetime but smoke and fire might
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Level Of Detail
• LOD for short• Gives the ability to have a low
quality and a high quality representation depending on distance– High requires more rendering work – Why do this when you are far away?
Copyright © 2015 Curt Hill
The Emitter
• An invisible 3D solid that spawns particles throughout its space
• A gun muzzle will be a small emitter– It appears that the muzzle flashes
come from a single point
• A rain cloud will be a large solid– The rain drops will start in a wide area
Copyright © 2015 Curt Hill
Multiple Emitters
• A particle emitter may have one or more actual emitters
• Multiples allow variations in appearance
• Rain drop splashes have four– Each of which has a different splash
pattern
• Cloud has just one
Copyright © 2015 Curt Hill
Using Particle Systems
• The UDK comes with more than a hundred particle systems
• Like any actor they are placed into the level by dragging from the content browser
• Adjust with the transformational and scaling widget
Copyright © 2015 Curt Hill
Cascade Editor
• This allows you to change the characteristics of a system
• These can be saved for future uses as well
• In the next image are four areas– 1 Preview Pane– 2 Emitter Pane– 3 Properties Pane (context dependent)– 4 Curve Editor Pane
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Cascade Editor
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Emitter Properties
Copyright © 2015 Curt Hill
Conclusion
• Lets make the rain fall
Copyright © 2015 Curt Hill