Precipitation
Defines a precipitation based storm (rain, snow, etc).
Precipitation
Rendering
float
Size of each drop of precipitation. This will scale the texture.
float
Size of each splash animation when a drop collides with another surface.
int
Lifetime of splashes in milliseconds.
bool
Set to true to enable splash animations when drops collide with other surfaces.
int
Length (in milliseconds) to display each drop frame.
float
The distance at which drops begin to fade out.
float
The distance at which drops are completely faded out.
bool
Set to true to make drops true (non axis-aligned) billboards.
bool
Set to true to enable shading of the drops and splashes by the sun color.
LinearColorF
Set to 0 to disable the glow or or use it to control the intensity of each channel.
bool
This enables precipitation rendering during reflection passes.
bool
Set to true to include the camera velocity when calculating drop rotation speed.
Collision
bool
Allow drops to collide with world objects.
bool
Allow drops to collide with Player objects; only valid if doCollision is true.
bool
Allow drops to collide with Vehicle objects; only valid if doCollision is true.
Movement
bool
Controls whether the Precipitation system follows the camera or remains where it is first placed in the scene.
bool
Controls whether drops are affected by wind.
float
Minimum speed at which a drop will fall.
float
Maximum speed at which a drop will fall.
float
Minimum mass of a drop.
float
Maximum mass of a drop.
Turbulence
bool
Check to enable turbulence. This causes precipitation drops to spiral while falling.
float
Radius at which precipitation drops spiral when turbulence is enabled.
float
Speed at which precipitation drops spiral when turbulence is enabled.
Public Static Attributes
bool
Disables rendering of all instances of this type.
bool
Disables selection of all instances of this type.
Public Functions
void
modifyStorm(float percentage, float seconds)
Smoothly change the maximum number of drops in the effect (from current value to numDrops * percentage).
void
setPercentage(float percentage)
Sets the maximum number of drops in the effect, as a percentage of numDrops.
void
setTurbulence(float max, float speed, float seconds)
Smoothly change the turbulence parameters over a period of time.
Detailed Description
Defines a precipitation based storm (rain, snow, etc).
The Precipitation effect works by creating many 'drops' within a fixed size box. This box can be configured to move around with the camera (to simulate level-wide precipitation), or to remain in a fixed position (to simulate localized precipitation). When followCam is true, the box containing the droplets can be thought of as centered on the camera then pushed slightly forward in the direction the camera is facing so most of the box is in front of the camera (allowing more drops to be visible on screen at once).
The effect can also be configured to create a small 'splash' whenever a drop hits another world object.
// The following is added to a level file (.mis) by the World Editor new Precipitation( TheRain ) { dropSize = "0.5"; splashSize = "0.5"; splashMS = "250"; animateSplashes = "1"; dropAnimateMS = "0"; fadeDist = "0"; fadeDistEnd = "0"; useTrueBillboards = "0"; useLighting = "0"; glowIntensity = "0 0 0 0"; reflect = "0"; rotateWithCamVel = "1"; doCollision = "1"; hitPlayers = "0"; hitVehicles = "0"; followCam = "1"; useWind = "0"; minSpeed = "1.5"; maxSpeed = "2"; minMass = "0.75"; maxMass = "0.85"; useTurbulence = "0"; maxTurbulence = "0.1"; turbulenceSpeed = "0.2"; numDrops = "1024"; boxWidth = "200"; boxHeight = "100"; dataBlock = "HeavyRain"; };
Precipitation
int numDrops
Maximum number of drops allowed to exist in the precipitation box at any one time.
The actual number of drops in the effect depends on the current percentage, which can change over time using modifyStorm().
float boxWidth
Width and depth (horizontal dimensions) of the precipitation box.
float boxHeight
Height (vertical dimension) of the precipitation box.
Rendering
float dropSize
Size of each drop of precipitation. This will scale the texture.
float splashSize
Size of each splash animation when a drop collides with another surface.
int splashMS
Lifetime of splashes in milliseconds.
bool animateSplashes
Set to true to enable splash animations when drops collide with other surfaces.
int dropAnimateMS
Length (in milliseconds) to display each drop frame.
If dropAnimateMS <= 0, drops select a single random frame at creation that does not change throughout the drop's lifetime. If dropAnimateMS > 0, each drop cycles through the the available frames in the drop texture at the given rate.
float fadeDist
The distance at which drops begin to fade out.
float fadeDistEnd
The distance at which drops are completely faded out.
bool useTrueBillboards
Set to true to make drops true (non axis-aligned) billboards.
bool useLighting
Set to true to enable shading of the drops and splashes by the sun color.
LinearColorF glowIntensity
Set to 0 to disable the glow or or use it to control the intensity of each channel.
bool reflect
This enables precipitation rendering during reflection passes.
note:This is expensive.
bool rotateWithCamVel
Set to true to include the camera velocity when calculating drop rotation speed.
Collision
bool doCollision
Allow drops to collide with world objects.
If animateSplashes is true, drops that collide with another object will produce a simple splash animation.
note:This can be expensive as each drop will perform a raycast when it is created to determine where it will hit.
bool hitPlayers
Allow drops to collide with Player objects; only valid if doCollision is true.
bool hitVehicles
Allow drops to collide with Vehicle objects; only valid if doCollision is true.
Movement
bool followCam
Controls whether the Precipitation system follows the camera or remains where it is first placed in the scene.
Set to true to make it seem like it is raining everywhere in the level (ie. the Player will always be in the rain). Set to false to have a single area affected by rain (ie. the Player can move in and out of the rainy area).
bool useWind
Controls whether drops are affected by wind.
float minSpeed
Minimum speed at which a drop will fall.
On creation, the drop will be assigned a random speed between minSpeed and maxSpeed.
float maxSpeed
Maximum speed at which a drop will fall.
On creation, the drop will be assigned a random speed between minSpeed and maxSpeed.
float minMass
Minimum mass of a drop.
Drop mass determines how strongly the drop is affected by wind and turbulence. On creation, the drop will be assigned a random speed between minMass and minMass.
float maxMass
Maximum mass of a drop.
Drop mass determines how strongly the drop is affected by wind and turbulence. On creation, the drop will be assigned a random speed between minMass and minMass.
Turbulence
bool useTurbulence
Check to enable turbulence. This causes precipitation drops to spiral while falling.
float maxTurbulence
Radius at which precipitation drops spiral when turbulence is enabled.
float turbulenceSpeed
Speed at which precipitation drops spiral when turbulence is enabled.
Public Static Attributes
bool isRenderable
Disables rendering of all instances of this type.
bool isSelectable
Disables selection of all instances of this type.
Public Functions
modifyStorm(float percentage, float seconds)
Smoothly change the maximum number of drops in the effect (from current value to numDrops * percentage).
This method can be used to simulate a storm building or fading in intensity as the number of drops in the Precipitation box changes. Parameters:
| percentage | New maximum number of drops value (as a percentage of numDrops). Valid range is 0-1. |
| seconds | Length of time (in seconds) over which to increase the drops percentage value. Set to 0 to change instantly. %percentage = 0.5; // The percentage, from 0 to 1, of the maximum drops to display %seconds = 5.0; // The length of time over which to make the change. %precipitation.modifyStorm( %percentage, %seconds ); |
setPercentage(float percentage)
Sets the maximum number of drops in the effect, as a percentage of numDrops.
The change occurs instantly (use modifyStorm() to change the number of drops over a period of time. Parameters:
| percentage | New maximum number of drops value (as a percentage of numDrops). Valid range is 0-1. %percentage = 0.5; // The percentage, from 0 to 1, of the maximum drops to display %precipitation.setPercentage( %percentage ); |
setTurbulence(float max, float speed, float seconds)
Smoothly change the turbulence parameters over a period of time.
Parameters:
| max | New maxTurbulence value. Set to 0 to disable turbulence. |
| speed | New turbulenceSpeed value. |
| seconds | Length of time (in seconds) over which to interpolate the turbulence settings. Set to 0 to change instantly. %turbulence = 0.5; // Set the new turbulence value. Set to 0 to disable turbulence. %speed = 5.0; // The new speed of the turbulance effect. %seconds = 5.0; // The length of time over which to make the change. %precipitation.setTurbulence( %turbulence, %speed, %seconds ); |