Houdini 20.5 Unreal

Using FBX Files

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FBX (Filmbox) files are an interchange format commonly used in the industry. This page gives some advice on how to import and export FBX files between Unreal Engine and Houdini.

Export from Houdini

To export data from Houdini to FBX files, you can use the File > Export dialog or the FBX render node.

These are important points when you export from Houdini to Unreal:

  • Make sure to export with 2018 SDK since it’s the current supported version by Unreal’s FBX import pipeline.

    • To export, select FBX|FBX201800 in the Version combo in the exporter dialog or ROP node parameters. If you export with another SDK version it might give you corrupted results or incompatibilities.

  • If you want to export Blend Shapes to Morph Targets in UE4, your asset’s network needs to be FBX Compatible. Make sure no nodes that modify the geometry after the blendshape nodes. Node that won’t block the blend shapes are Nulls, switches, caches, attributes, skin deform or merge nodes. Nodes that alter the geometry such as subdivide might block the export.

    • To export and ignore all the incompatible nodes, use Force Blend Shapes Export.

  • Blendshape animations can be exported but the shapes themselves can’t be time dependant in Houdini

  • Exporting vertex animations prevents blend shapes export, unless the Force Blend Shapes Export option is enabled.

Import into Unreal

Some points when you import FBX files exported by Houdini into Unreal:

  • There’s a difference in length unit between Houdini (1 unit = 1m) and Unreal (1 unit = 1cm). Make sure to use a uniform scale of 100 in the FBX import dialog.

  • You don’t have to take into account the difference in coordinate systems between Houdini and Unreal when importing FBX files created by Houdini, as the FBX exporter in Houdini has already taken care of this.

Unreal

Getting started

Basics

Using Houdini Engine

Scripting

Reference