ldraw2houdini

LDraw2Houdini

Import LDraw files directly into Houdini

Source individual parts or import entire models with one-button shelf tools!

Watch YouTube Showcase Video

Features

• Import individual bricks & entire models
• Logo on studs
• LDR, L3B & MPD file support: mpd files contain multiple sub models, referenced by a main model
• Instancing support: duplicate bricks are automatically packed and the color is read from the point data
• Imperfections: if importing a model, the bricks are not perfectly stacked/aligned to each other for a more realistic look. Bricks can also randomly yellow due to age.
• Injection points: options to procedurally add injection marks either on stud or on walls (vintage bricks ~70s and older)
• Gaps between bricks: bricks can be slightly squashed to get tiny gaps between them
• Slope support slopes are automatically detected so they can get a grainy texture
• Bevel and subdivison support: geometry is automagically cleaned up as much as possible and LDraw lines are used to determine edges that need to be beveled to allow proper subdivision
• Auto caching every imported part will automatically be cached in LDraw library; Importing times will decrease the more LDraw2Houdini is used.
• Auto generate textures for prints/stickers for modern cg workflows
• Auto uvs
• Material properties: simple config file to define softness, graininess and roughness for individual parts
• Solaris + Karma example scene contains MaterialX shader showcasing how to create high quality renderings
• ACES colorspace: LDraw colors are converted to acescg

Requirements

• Houdini 20.5 (Py 3.11) – Other versions might work, see Optional Step 8.
• SideFX Labs for auto uv feature
• OCIO ACES colorspace configuration for Houdini

Installation

1. Download the latest release

2. Unpack to a directory called ldraw2houdini

    # Windows C:\\Users\\<username>\\Documents\\git\\ldraw2houdini 
    # Linux ~/git/ldraw2houdini
   

3. Download LDraw parts library – (complete.zip)

4. Unpack to a directory called ldraw

    # Windows C:\\Users\\<username>\\Documents\\ldraw
    # Linux ~/ldraw
   

5. Download ldraw2houdini.json from release page. Place it in the Houdini packages folder.

6. If packages folder doesn\’t exist create it yourself.

    # Windows C:\\Users\\<username>\\Documents\\houdiniXX.X\\packages
    # Linux ~/houdiniXX.X/packages
   

7. Launch Houdini – Happy ldrawing!

Optional Steps

8. Make sure you have Houdini 20.5 Python 3.11 installed. If you are running older or newer versions of Houdini and/or Python you have to rename the python3.11libs folder accordingly. I.e. if your Houdini Python version is 3.9 rename it to python3.9libs

9. If you placed anything in different paths, adjust ldraw2houdini.json accordingly.

   • LDRAW2HOUDINI needs to point to the path of this plugin

   • LDRAW_LIB needs to point to the LDraw library

   • Under Windows $HOME points to C:\\Users\\<username>\\Documents

   • Under Linux $HOME is ~/

           {
           \"env\": [
                   { \"LDRAW2HOUDINI\": \"$HOME/git/ldraw2houdini\" },
                   { \"LDRAW_LIB\": \"$HOME/ldraw\" },
                   { \"LDRAW_CACHE\": 0 }
           ],
           \"path\": [
                   \"${LDRAW2HOUDINI}\"
           ]
           }
     

10. Set LDRAW_CACHE to 0 or 1 to enable/disable caching. This will write bgeo files to $LDRAW_LIB/bgeo. Remember to delete this folder if you update your LDraw parts library.

11. If you install a new release and want to upgrade your hdas in an existing scene run the Upgrade Brickini HDAs Shelf Tool

12. See release notes for more details and explanations of specific features

Quickstart Guide

Import a single part

1. Create a Brickini LDraw Part node inside a Geometry node in SOP context
2. Type a cool part number into the Part parameter: 2546p01
3. Change Material parameter to red
4. Look at that awesome classic parrot

Import an entire model

1. Add the Brickini Shelf to your toolbar

2. Click LDraw Model or LDraw Model Dynamic

3. Choose an LDraw model file

4. Prints won\’t show up in the viewport, if bricks are packed (default) but are supported when rendering with Karma/Solaris

5. Example scene with Karma material can be found here:

    ldraw2houdini/resources/example_files/example_scene.hiplc
   

Contributions

• LDraw Model HDA (Dynamic mode): Kai Stavginski
• Auto caching concept/idea: Kai Stavginski

Resources

• LDraw Official Model Repository
• Official sets made in LDraw
  Eurobricks Thread

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