Wednesday, July 8th, 2020 Posted by Jim Thacker

SideFX ‘backports’ new features to Houdini 18.0

SideFX has ‘backported’ features in development for the “next major release” of the software to Houdini 18.0, the current stable version of the procedural 3D software.

The move gives users access to a neat new topology transfer system, support for fog in the OpenGL viewport, and support for random walk subsurface scattering in the Karma renderer.

All the new features are described as production-ready, and have been available since Houdini 18 Build 499.

Making new features from Houdini 18.5 available early for use in production?
Build 499 actually shipped last month – at the time of writing, the latest daily release is Build 521 – but we overlooked it at the time, since SideFX’s incremental updates tend to be bugfix releases.

This one is considerably more significant, adding new features throughout Houdini’s toolsets.

As far as we can remember, this is the first time that SideFX has backported features in this way, presumably because of the unusual situation during COVID-19 restrictions.

Under its usual schedule, the firm releases a major update to Houdini every six to nine months.

Houdini 18.0 having shipped last November, that would have put us on course for Houdini 18.5 around now – presumably the “next major release” from which the new tools have been backported as a stopgap update.

New Topo Transfer node transfers clean all-quad topology to raw 3D scan data
New features now available in the production release of the software include Topo Transfer, a neat new system for deforming a source mesh organically to match the dimensions of of a target mesh.

In the video above, it looks reminiscent of Wrap, R3DS’s popular standalone topology transfer tool, enabling users to transfer clean, all-quad topology from a stock base model to a 3D character scan.

As with Wrap, automating the transfer process should greatly reduce the manual work needed to convert raw scan data into animation-ready geometry.

Users can also define corresponding landmark points on source and target meshes to improve the quality of the results the Topo Transfer SOP generates.

Modelling: new Path Deform system
Other new modelling features backported in Houdini 18 Build 499 include the Path Deform SOP.

As the name suggests, it deforms geometry along a path, with use cases range from creating 3D text to modelling long linear objects like belts or chains.

Users can apply secondary deformations like twisting or scaling to the curve-deformed model, and both the mapping of the model to the curve and the curve itself can be animated.

Rendering: new viewport fog system, support for random walk subsurface scattering
New viewport features include a fog system with controls for density, opacity, height and depth range.

The fog interacts with scene lighting in real time, and can be rendered to disk using the OpenGL ROP, which now supports 64-bit precision.

Other rendering changes include support for random walk subsurface scattering in Karma, the new USD-native render engine introduced in Houdini 18.0.

Although Karma is still officially in beta, the new system is not available in Mantra, Houdini’s existing renderer, which it is ultimately intended to replace.

According to SideFX, random walk preserves detail more accurately than the other subsurface scattering algorithms available in Houdini’s Principled Material, avoiding energy loss around fine edges.

Karma also gets support for the Ptex texture mapping system.

Animation: new animation timewarping tools, updates to crowd simulation
Animators get a new Dynamic Warp CHOP for motion editing.

The new channel node timewarps the motion of a source animation clip to match that of a reference clip: for example, to sync the animations of two characters so they walk in stride.

The crowd simulation toolset also gets a number of updates, including the option to import animation clips from one or more USD skeleton primitives via the Agent Clip SOP.

Workflow, performance and pipeline integration improvements
There are also a number of workflow and performance improvements, particularly to the destruction toolset, the Procedural Dependency Graph, and Solaris, the new look dev toolset introduced in Houdini 18.0.

Pipeline improvements include enhancements to FBX export, including the option to export files using different axis conventions to Houdini, and support for the 59.94 fps frame rate.

Outside of the core application, the Houdini Engine for Unity plugin gets a new SessionSync feature, which live links the Unity game engine to a Houdini Engine session running in Houdini itself.

Changes made in one application are then propagated to the other in real time.

Pricing and system requirements
SideFX hasn’t announced a release date for Houdini 18.5, or any other major future update. The current stable version, Houdini 18.0, is available for Windows 8+, macOS 10.13+, and Linux distros.

The full edition, Houdini FX, costs $4,495 for a node-locked licence; $6,995 for a floating licence. Houdini Core, which lacks simulation tools, costs $1,995 for a node-locked licence; $2,995 for a floating licence.

There is also a free Houdini Apprentice learning edition and a lower-cost, rental-only Houdini Indie edition. Both save in their own file formats and have feature restrictions. See a product comparison table here.

Read more about the backported features in Houdini 18 Build 499 on SideFX’s blog