modifier_influence

The modifier influence can be used to replace, add, multiply or clamp the value of a simulation property like voxel_density,point_velocity, or point_size.

To use this node, plug its output into the influences input of a simulate node like simulate_aero, simulate_particles, or simulate_mpm.

Inputs

influence

One may optionally connect an influence field's out_influence into this port. For example a mask_influence node could be connected to mask the effect of this influence. Any number of influence fields may be added to the daisy chain to build a complex field.

enable

Turn off to disable the effect. Disabling makes it a pass through node. Note that any other influence fields connected to the influence input port will still be active when this is disabled.

property

The name of the simulation property to modify.

operation

The math operation to apply to the specified simulation property, using the specified value:

• Replace: Substitute the current value with the specified value
• Multiply: Multiply the current value by value
• Add: Add value into the current value.

value

This is the value to replace, multiply or add by. In general it should be the same type as the property, but one could multiply a float3 property like point_velocity by a simple float value, which would have the effect of scaling the speed.

rate

This is how quickly the operation is applied. For example replace will not immediately set the simulation to value unless the rate is very high. You can connect a ScalarField to vary the effect over space.

enable_clamp

If this is enabled then the values for the defined property are clamped to be within the specified min and max values. The clamp does not use the rate but immediately clamps the values, even with a rate of zero. To only do a clamp with no math operation one can make the rate zero. Clamp currently only works for float and float3 properties. For float properties one can clamp with a float or scalarField type for both min and max. For float3 properties the min and max should be float3 or vectorField.

min

The minimum value to clamp to (only has an effect when enable_clamp is on). This may be float, float3, scalarField or vectorField.

max

The maximum value to clamp to (only has an effect when enable_clamp is on). This may be float, float3, scalarField or vectorField.

Outputs

out_influence

An output influence object that one can connect to simulation nodes or other influence nodes.