gen on surface

 

 

Use this generator node when you need to create particles on object surface. It allows particle placement of vertices, edges or faces.

 

Note: Particle generator output pins and data are available only when the particle is created. To access particles continuously, use the get particle group node.

 

 

[Inputs]

 

Enabled - Enable or disable node evaluation.

 

Particle Group - Generated particles will belong to this this group.

 

#Input (Object) - This pin is by default set to Object where particle in the input will be generated on objects from the list. If you right click on this pin you can change it to Input (Shape) which will then use particle shape to generate new particles.

 

Cluster By - Each particle is automatically assigned to a cluster. There are several options how you can group particles into clusters.

• Constant - All particles that this node creates are assigned to the same unique cluster group.
• Simulation Frame - Only particles that are created on the same frame are assigned to the same unique cluster group.
• Object - Particles are assigned to the same unique cluster group based on the object they are created on.
• Particle - Each particle is assigned to its own unique cluster group.

 

 

Objects

Objects by RegEx - You can use regex (regular expressions) to select objects in the scene. This is a very powerful tool to automatize the process.

 

Objects - List of objects that you want to use. Double click on object name to remove it from the list or use Remove button. You can select multiple objects.

 

Animated Mesh - Enable this option if objects are animated in any way. Keeping this option disabled results in faster computations.

 

 

Generate

Time Start - Emission start time. There will be no emission before this frame.

 

Time End - Emission end time. There will be no emission after this frame.

 

Location Type - There are several options how particles will be distributed over objects: Vertex, Edges, Faces, Faces Random and Faces Random Uniform.

 

Birth Rate - Number of particles that will be generated at each frame. This option is available only with Faces Random and Face Random Uniform Location Type.

 

Generate % - Lower this value if you don't want to create particles on each location. This option is available only with Vertex, Edges and Faces Location Type.

 

Position Jitter - Alters a location where particle will be created. This option is available only with Vertex, Edges and Faces Location Type.

 

Use Surface Offset - Place particle above the mesh surface.

 

Surface Offset Min - Minimum distance above the mesh surface where particle can be placed.

 

Surface Offset Max - Maximum distance above the mesh surface where particle can be placed.

 

 

Location Filtering

Use Selected Faces - When enabled, particles will be created only on selected faces (depending on the location type).

 

Use Material ID - Enable this option if you want to create particles only on faces with user defined Material ID.

 

Material ID - Specify the material ID.

 

Use Texmap - Use this option if you want to generate particles on locations with specific color.

 

Texmap - Texture to retrieve color from.

 

UVW Map Channel - Mapping channel for Texmap evaluation.

 

Map Color - Particles will be created only on locations where texture color matches this color.

 

Map Color Thresh - Map Color threshold.

 

Use Slope - Allows particle placement at locations defined by the angle between surface normal and user defined "Slope Up" vector.

 

Slope Up - Defines the "up" vector. For a terrain, this vector will be along the Z axis.

 

Slope Min - Minimum slope angle.

 

Slope Map - Maximum slope angle.

 

 

Properties

Life Span - Particle life span in frames. Particles that are older than its lifespan will be automatically deleted.

 

Life Span Var % - Life Span variation.

 

Speed units/s - Particle speed in current 3ds max units per second.

 

Speed Var % - Particle speed variation.

 

Align to Normal - Particle will be aligned to the mesh normal.

 

Custom Direction - By default, particles will travel in direction of the normal where they're created. Enable this option to specify their travel direction.

 

Direction - Particle initial travel direction.

 

Direction Var - Direction variation angle in degrees.

 

Size - Particle size.

 

Size Var - Particle size variation.

 

Density - Particle density. Particle mass is computed from particle size and density so that bigger particles will have bigger mass.

 

Density Var % - Density variation.

 

UVW Map Channel - This channel is related to the output UVW coordinates. It is not used unless output UVW and related pins are connected.

 

 

[Outputs]

 

Particle Stream - Generated particle stream.

 

Shape Particle - This pin is visible if Input (Shape) is used. In that case it will output the shape's particle on the output so that you can perform additional operations with that particle if required.

 

Particle # - Generated particle index. It goes from to Total#-1.

 

Total # - Total number of particles that will be generated at current frame.

 

Position - Position of generated particle.

 

UVW - UVW coordinates of UVW Map Channel at the location where particle was generated. Often used by nodes such as Texmap and Texmap Gradient.

 

Normal - Vertex normal at the location where particle was generated.