New particle fluid emitter and particle fluid sink tools on the shelf.

Much faster particle fluid surfacing (up to 60 times faster).

New particle fluid surfacing options, such as stretching the surface in the direction of particle velocity. See the Particle fluid surface node.

Threaded cloth collision detection for faster cloth simulation performance.

SDF and primitive support for cloth collision for more reliable cloth-volume interaction.

You can now shape muscles with interactive handles. See the Muscle object.

New Sticky blend object lets you parent an object to the blended position of two or more Sticky objects.

Faster interaction in the channel editor.

You can delete all animation on the scoped channels by right-clicking in the channel list and choosing Delete all channels.

Improved direct editing of keys on the timeline.

Faster animation and deformation.

Selecting a channel in the channel editor selects the node to which the channel belongs.

When you select linear or ease for a curve segment in the channel editor, the channel editor now set the segment to bezier and move the handles to achieve the desired curve shape, rather than using opaque linear or ease curve functions. This lets you choose linear or ease and then edit the curve shape.

Channel editor now supports importing/exporting keyframe animation data.

Rich library of production-quality materials.

Use of native locks improves multi-threaded rendering performance on Windows.

Better performance when rendering with many (>32) open texture files.

Support for rendering of triangle strip primitives.

Support for rendering vertex normals.

JPEG quality control on output drivers.

Better automatic node layout in VOPs.

Many minor enhancements to the file chooser, including a more usable image chooser mode and better handling of image sequences.

Much faster selection of large numbers of nodes in the network editor.

Support for Houdini in the system application menu on Gnome and KDE, or any other desktop using the freedesktop.org menu standard.

Default color scheme is now darker with lower contrast. Support for selectable color schemes.

Added object type visibility menu to display toolbar (right side of 3D viewer pane).

Smaller file sizes on some 8- and 16-bit LZW-compressed images.

New attribute handling API in the HDK.

More robust and reliable Cookie (boolean) node.

You can now connect a surface to the middle input of the Fur node and the node will automatically create hairs, without the need to specify guide hairs or create attributes.

Poly reduce enhancements, including support for N-sided polygons, topological weight, and painted importance attributes.