Houdini 20.0 Nodes Geometry nodes

DOP Import Fields 2.0 geometry node

Imports scalar and vector fields from a DOP simulation.

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Since 19.5

The DOP Import Fields SOP is designed to streamline the common operation of importing many fields from fluid simulations into SOPs.


When importing simulation data, you may have extra attributes that you do not need to save to disk. The delete attributes will cull these attributes.


Point, primitive, vertex, and detail attributes which match will be deleted. However, the point P attribute is always kept. So, to delete all except P and velocity (v), use the string: * ^v.

If you do not require the full precision of 32 bit float attributes, you can down cast them at this point as well. See the AttribCast SOP help for more information.

After importing the fields, you can apply some compression rules before saving them to disk. Some fields, such as density, may have different requirements for tolerances than others, such as velocity. Sp, multiple compression groups can be created here. Each group can use the @name=density style group field to select the desired fields.

Detailed descriptions of these options is found in the Volume Compress SOP.


DOP Network

The DOP Network to extract the fields from.

DOP Node

All the objects created by this node will be imported. This is the equivalent of the dopobjscreatedby expression. This overrides the Default object.

Default Object

If the Object specified in the individual import options is blank, this default object is used instead. This is a DOP Object specifier.

Transform Geometry With Position Data

Applies the translation and rotation described by the simulation object’s Position subdata.

Transform Geometry With Geometry Data

Use the transform embedded in the Geometry data attached to the simulation object. This transform is usually set when Use Object Transform is enabled on the geometry data.

Add DOP Object Path Attribute

Adds a dopobject primitive string attribute, which contains the path of the DOP Network followed by the DOP object id (or the relationship name, when importing a relationship). A doppath detail string attribute is also created, which contains the path of the creator DOP node for the primary object being imported.

Compute Min/Max Values

The minimum and maximum value of each volume primitive will be computed and stored on a primitive attribute of that name.

Import Simulation Settings

Certain global simulation settings, such as the timescale and rest field ratios, can be imported as detail attributes. This allows the resulting .bgeos to be rendered without needing to keep track of the settings of the simulation that created them.


Quickly populates the field choices to common defaults.


This will wipe out any existing imports.


Fields to Import

How many fields to import.


Toggles whether this specific field should be imported.


Controls how the volume will appear in the viewport. Ancillary data volumes like velocity and rest fields are often useful to mark as invisible so they are available to mantra but don’t get in the way of viewing.


The object to retrieve a field from. If blank, the default object is used instead.


The scalar or vector field to extract from the object. It will be properly named, ie, the vel field will create vel.x, vel.y, and vel.z named volumes. It will also be in a group named after the DOP object.

While this is designed around importing fields, any geometry can actually be imported here. For example, Geometry will import the geometry associated with an RBD object.

See also

Geometry nodes