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The <particle_system> node

Function

The particle_system node makes it possible to create a particles system.

The particle term is considered in the most general sense. In physics, a particle generally has a mass and/or one charge and is subjected to the gravitation laws or to the electromagnetic forces which influence its position and its speed in space and time. The particles movement of Demoniak3D's particles system is based on the true equations of physics, which gives the particles very realistic movements.

The particles system is very useful to create snow effects, rain or smoke, explosions and many other visual effects.

Objects called emitters generate particles at each frame, while other objects called obstacles and actions are used to modify the direction and the speed of the particles. Actions, obstacles and emitters which control the behavior of the particles are located in plugins.

General syntax

<particle_system
	name=""
	particle_texture=""
	num_particles="2000"
	active="TRUE"
	point_sprite="FALSE"
	blending_src_factor="BLENDING_FACTOR_SRC_ALPHA"
	blending_dst_factor="BLENDING_FACTOR_ONE" >

	<add_action
		name="myChild" />
	
	<add_emitter
		name="myChild" />

	<add_obstacle
		name="myChild" />
</particle_system>

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particle_system element

particle_system is the xml tag that defines a particle_system node.

Attributes:

• name - [STR127] - name of the node. This name will make it possible to refer this node throughout the XML script.
  
  
• num_particles - [INTEGER] - specifies the maximum number of particles that the particles system has to manage. The more they will be, the longer the calculation will last, which will involve a fall of the FPS (frames per second) - default value: 2000
  
  
• particle_texture - [STR127] - name of the texture node involving textures to be applied to each particle of the system.
  
  
• active - [BOOLEAN] - enables (TRUE) or disables (FALSE) the particles system - default value: TRUE
  
  
• blending_src_factor - [ENUM] - specifies the source blending factor - default value: BLENDING_FACTOR_SRC_ALPHA
  blending_dst_factor specifies the blending destination factor in the blending equation:
  C = Cs*Sf + Cd*Df
  where C is the final (R, G, B, A) color, Cs the (Rs, Gs, Bs, As) source (or entering) color and Cd the (Rd, Gd, Bd, Ad) color present in the framebuffer.
  Sf is the (Sr, Sg, Sb, Sa) blending source factor and Df is the (Dr, Dg, Db, Da) blending destination factor.
  
  • BLENDING_FACTOR_ZERO: (0 0 0 0)
  • BLENDING_FACTOR_ONE: (1 1 1 1) (default value)
  • BLENDING_FACTOR_SRC_ALPHA: (As, As, As, As)
  • BLENDING_FACTOR_ONE_MINUS_DST_ALPHA: (1-Ad, 1-Ad, 1-Ad, 1-Ad)
  • BLENDING_FACTOR_ONE_MINUS_DST_COLOR: (1-Rd, 1-Gd, 1-Bd, 1-Ad)
  • BLENDING_FACTOR_ONE_MINUS_SRC_ALPHA: (1-As, 1-As, 1-As, 1-As)
  • BLENDING_FACTOR_DST_COLOR: (Rd, Gd, Bd, Ad)
  • BLENDING_FACTOR_DST_ALPHA: (Ad, Ad, Ad, Ad)
  • BLENDING_FACTOR_SRC_COLOR: (Rs, Gs, Bs, As)
  • BLENDING_FACTOR_ONE_MINUS_SRC_COLOR: (1-Rs, 1-Gs, 1-Bs, 1-As)
  
  First remark: The mixture of the colors will be effective only if the blending is activated.
  Second remark: Unlike other objects (mesh, hud), blending is always activated in a particles system.
  
  
• blending_dst_factor - [ENUM] - specifies the blending destination factor. Please refer to blending_src_factor to check the acceptable values - default value: BLENDING_FACTOR_ONE
  
  
• point_sprite - [BOOLEAN] - enables (TRUE) or disables (FALSE) the high performance rendering of the particles. This high performance mode is available only if the graphics controller supports the OpenGL 1.5 point_sprite extension. To check this capability, please use the HardwareInfos utility, delivered with Hyperion - default value: TRUE
  
  
• group - [STR127] - name of the group in which to add the current node. A group makes it possible to control the behavior of several objects in a single way.

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add_emitter element

add_emitter allows to add an emitter to the particles system. A particles system can have several emitters of the same type or of different type.

Attributes:

• name - [STR127] - name of the emitter

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add_action element

add_action allows to add an action to the particles system . A particles system can have several actions of the same type or of different type.

Attributes:

• name - [STR127] - name of the action

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add_obstacle element

add_obstacle allows to add an obstacle to the particles system. A particles system can have several obstacles of the same type or of different type.

Attributes:

• name - [STR127] - name of the obstacle