4.5 KiB
Set Attribute
Menu Path : **Attribute > Set > [Add/Blend/Inherit/Multiply/Set] <Attribute> **
The Set Attribute Block is a generic Block that allows you to write values to an attribute using composition.
You can either set the value of the attribute directly, or use two different random modes, Uniform and Per-Component, to set the attribute to a random value.
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Uniform calculates a single random number in range 0 to 1 then, to produce the final value, uses the random value to interpolate between the two range values (A and B).
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Per-Component calculates a random number in range 0 to 1 for each component in the attribute type then, to produce the final value, uses each random value to interpolate between each component of the two range values (A and B).
You can also use this Block to inherit a source attribute and set it directly to the current attribute. For instance, you can inherit the position of a parent particle, and set it to particles generated from a GPU Event. If you set the Source setting to Source, the Block does not display any input properties for the attribute and instead uses the source attribute value (or the default source attribute value if the attribute is not present).
Block compatibility
This Block is compatible with the following Contexts:
- Initialize
- Update
- Any output Context
Block settings
| Setting | Type | Description |
|---|---|---|
| Attribute | Attribute (Inspector Only) | (Inspector) Specifies the attribute to write to. |
| Composition | Enum (Inspector Only) | (Inspector) Specifies how this Block composes the attribute. The options are: • Set: Overwrites the position attribute with the new value. • Add: Adds the new value to the position attribute value. • Multiply: Multiplies the position attribute value by the new value. • Blend: Interpolates between the position attribute value and the new value. You can specify the blend factor between 0 and 1. |
| Source | Enum (Inspector Only) | (Inspector) Specifies the source of the attribute. The options are: • Port: Calculates the value from the Block’s input property ports. • Source: Takes the value from the source attribute of the same name. |
| Random | Enum | (Inspector) Specifies how the Block calculates the value to compose to the attribute. The options are: • Off : Does not calculate a random value for the attribute. Uses the value you provide in the input directly. • PerComponent: Calculates a random value for each of the attribute's components. • Uniform : Calculates a single random value and uses it for each of the attribute's components. |
| Channels | Enum | Specifies which channels of the attribute to affect. This Operator has no effect on channels you do not specify with this setting. This setting is only visible if the Attribute you set is one with channels. |
Block properties
| Input | Type | Description |
|---|---|---|
| <Attribute> | Depends on the attribute | The value to compose to the attribute. This property only appears if you set Source to Port and Random to Off. |
| A | Depends on the attribute | The first end of the random range the Block uses to calculate the value for the attribute. This property only appears if you set Source to Port and Random to PerComponent or Uniform. |
| B | Depends on the attribute | The other end of the random range the Block uses to calculate the value for the attribute. This property only appears if you set Source to Port and Random to PerComponent or Uniform. |
| Blend | Float (Range 0..1) | The blend percentage between the current position attribute value and the newly calculated position value. This property only appears if you set Composition to Blend. |