Houdini 20.0 Nodes Geometry nodes

File Merge geometry node

Reads and collates data from disk.

Since 12.0

The output of a distributed DOP simulation is often multiple sequences of geometry files. Each frame of the volume or particle simulation is broken into several files. The File Merge SOP reassembles these into a single piece of geometry.


Geometry File

The name of the file to read. It is important it has the keyword $SLICE in its name. This will be replaced by the merge number, independent of any current value of that variable.


This cannot be a channel reference or the $SLICE expansion will fail.

Reload Geometry

Force a reload of the file.

Merge Range

The $SLICE variable in the file name will be replaced by this sequence of numbers. The first is the start, the second the end, and the third the increment. For example, to load files 0..3 from disk, the value should be 0, 3, 1.

Delete Points from Other Files

Particle simulations store a particle slice attribute when distributed. Since particles will show up in more than one file, you will get duplicate particles if you just merge them all together. This option will delete any particles whose slice attribute doesn’t match the current merge number.

Missing File

What should be done if the specified file does not exist on disk. By default, if no file of the given name exists, the SOP will error. This can be troublesome in a network that can recover from the error. In these cases the behavior can be set to No Geometry so only a warning is posted.


Some file formats, in particular .bgeo and .geo, contain meta-data in the header than can be loaded without loading the entire file. This is useful for dealing with large data sets.

All Geometry

Loads the whole file.


Creates one point if the file loads successfully and attach attributes for each named component of the meta-data.

Info Bounding Box

Tries to build a bounding box using the information stored in the header of the file.

Merge Variable

The variable name in the Geometry File that will be replaced by each number in the Merge Range.

Cache Length

The number of geometries to cache. The same File SOP is used internally for each of the slices; so this should be a multiple of the number of slices. For example, if merging four slices over ten frames, the cache length should be forty.

See also

Geometry nodes