Deborah R. Fowler

Houdini - Instancing/Layout

Posted Aug 11 2026 Updated Aug 28 2026
Keywords: instancing, layout, new in 22

Example file pertaining to the discussion of layout with all files including the separate hipnc without usd files. zip Layout.zip hipnc scatter.hipnc

The preferred workflow over instancing came with the introduction of packed primitives in H13. Then with Solaris we moved into USD (packed comes full circle from instance nodes to packed to instancing in USD). As of Houdini 22 they introduced a layout tool bursh (paint instances) and scatter instances.

There is an excellent video introducing some of the new improvements to Solaris in Houdini 22. Along with this are some things that require some background. https://www.youtube.com/watch?v=6EaIVsFOLVg&t=218s

  • What is Hydra?

    Pixar's imaging and rendering framework built into OpenUSD. Karma is Houdini's Hydra render delegate (renderer).

  • What is Karma?

    Houdini's ray tracer (physically-based path tracer) in CPU/XPU. It uses USD and is intended to replace Mantra. Karma CPU provides some support for vex-based shaders, Karma XPU does not - MaterialX shaders are used.

  • What is Vulkan?

    "Improved" graphics API for interactive viewport display (used to be OpenGL).

Where should beginners start?

Start with traditional geometry SOPs (Surface Operators) before learning Scatter Instances in LOPs (Lighting Operators).Understanding standard geometry points and attributes provides the essential foundation needed to control advanced render-time scattering.

SOPs provide:
  • default visual feedback - scatter, copy to points you can inspect and manipulate
  • attribute concepts - @pscale, @N and @orient
  • easy to examing the point and vertices data for debugging purposes
  • many standard pipelines (modeling, rigging, simulation) rely on SOPs
LOPS/Solaris provide:

LOPS scatter instances are a way to use layout in the Solaris environment - useful when using massive scale scens like forests, millions of assets and real time optimization.

Solaris (as per the keynote) now is consider lighting, look dev and layout! That last one is considered the "third arm" - with RBD and hydra support in H22.

Ways to do layout:
  • In SOPS with copy family and use packed for efficiency
    • scatter node (can be combined with attribute paint was well for placement)
    • scatter align (had controls for orientation and scale randomization - could use above and use randomize attribute)
    • scatter in TextureMap (use a texture map to define where to scatter)
    • also USD component building is now in SOPs as they recognize not everyone is working in LOPs. The pivots are bettter and it creates a USD proxy.
  • In LOPS using USD Instancing
  • Point instancer
  • Scatter instances - has built in camera frustrum masks
  • Layout tool brush - paint instances - similar to Unreal's foliage tool brush (which can be applied to things other than foliage)

So what about paint instances (have to be in LOPs) and component builder (can be done in SOPs or LOPs) To use the paint instance node you must be in lops, feed your surface you are painting on into the node and then the teddy bear icon under protoypes shows a catalog of objects to select from. Select and paint - you must pick your settings before painting but there is a delete and other tools such as comb which allows you to "paint" orientation.