Custom File Readers

I created this repository to share some custom file readers I've made for houdini during my tenure at DASH. Most of these have to do with reading medical or 3D printing data sets. Hopefully some of you will find this useful!

Feel free to reach out with any questions about installation and use.

1. .3mf Reader
2. NRRD Reader

.3mf Reader installation and use

This file reader will import meshes from .3mf formatted files, and load them into houidini.

Notably, this only supports meshes. It will not correctly load sliced files, or beam lattice files.

It will load vertex color and UV coords appropriately, but material assignements and texture information has to be set up separately.

Installation

1. Copy the sop_Read3mf.hda from the otls folder to an otls folder on your $HOUDINI_PATH
2. Install the Lib3MF python library to a python3.7libs folder on your $HOUDINI_PATH
3. Place your lib3mf shared object file (generally .so for linux or .dll for windows) in an accessible location.

Usage

1. Search for the Read_3mf sop node from the tab menu in your geometry node inside of houdini.
2. Select your file using the file picker, and load your file.
3. Select your shared object location using the second file picker on the node

Sample files taken from 3MFConsortium on GituHub

NRRD Reader Installation and use

This file reader will import volumes using the nrrd format, and load them into Houdini.

You have the choice to use either Houdini's built in volumes or VDB's

Installation

1. Copy the sop_ReadNRRD.hda from the otls folder to an otls folder on your $HOUDINI_PATH
2. Install pynrrd to your houdini environment:

Option 1: By default, the node will install the pynrrd package using pip from within the module itself. To do this:

• create a new Read_NRRD node
• Try to import a volume, it should faile with a message saying nrrd not found.
• Restart Houdini, and everything should be working.

Option 2. Alternatively you can install nrrd manually to your Houdinig Python environment.

• run hython -m pip install pynrrd from a command line to use pip to install the pynrrd package

Usage

1. Search for the Read_NRRD sop node from the tab menu in your geometry node inside of houdini.
2. Select the type of volume you wish to create, VDB or Houdini Volume

(Note: many medical datasets use value ranges outside of what houdini represents by defauly, if you have issues with the appearence of your volume after importing it, try adjusting the value range)

Sample files taken from 3D slicers sample dataset.