Houdini 20.5 What’s new What’s new in Houdini 20

What’s new Feathers

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Feather nodes
Groom nodes
Content library examples

Houdini’s brand new feather system is a complete set of GPU-powered tools that allows for the efficient creation of highly detailed feathers. You can draw freehand curves, but also use reference images to create a full set of different types like wing feathers, decorative plumes, down, coverts, etc.

A basic shape, made of several curves, is turned into a realistic feather model with shaft and barbs (barbs are thin filaments that grow from the shaft). Appropriate nodes let you shape the barbs, add curvature, orientation or noise to get the typical looks of different feather types. Sophisticated methods let you create UVs for complete feather sets in one pass for texturing. A wide range of attributes lets you manipulate feathers and parts of them through wrangles and noise. This way you can add frizz to the barbs, or randomize length and curvature.

The feathers are then painted onto a character. You can interpolate between various feather types, adjust scale and orientation, and apply a wide variety of grooming tools to get the desired look. Guide feathers, preview modes, low-res proxies for both the feathers and the underlying character geometry, together with other tools ensure a fast workflow. A new radial menu provides quick access to the most important grooming tools.

More than 20 nodes give you all the necessary tools for the creation of believable feathers.

Houdini’s feathers also work with animated and moving characters. All physics and simulation work on the feathers, e.g. for wind, is done by Houdini’s versatile Vellum solver.

Feathers and groom by Andriy Bilichenko

A Feather Procedural translates your feather work into high-resolution objects directly at render time. The procedural is renderer-agnostic and works with any Hydra delegate. With Houdini’s new fur shader with medulla support you can achieve outstanding results in Karma GPU and XPU.

Feather nodes ¶

Feather Barb Tangents SOP computes tangent space information for the surface spanned by barbs.
Feather Barb Transform SOP transforms barb vectors between feather space and object space.
Feather Clump SOP adds clumps and splits to a feather.
Feather Deform deforms feathers by using other feathers or polygon surfaces.
Feather Deintersect SOP moves intersecting feathers apart and separates them.
Feather Instance Pool SOP creates a feather primitive for each combination of template weights found in the input curves.
Feather Match Uncondensed SOP transfers attributes from uncondensed (expanded) feathers to single-curve feathers.
Feather Minimum Distance SOP finds the closest point to each barb point on another geometry.
Feather Noise SOP adds noise to the barbs of a condensed feather. The noise amount can be controlled separately along each axis (along normal, tangent, or bitangent).
Feather Normalize SOP normalizes the length and straightens feathers.
Feather Primitive SOP generates feather primitives (Agent primitives with GPU-skinning).
Feather Ray SOP finds the closest point on some other geometry for each point on a feather, find the closest point on some other geometry. Perfect for projecting UVs from other geometries to a complete feather set.
Feather Resample SOP controls the number of points on the shaft and its attached barbs as a post process.
Feather Shape Organize SOP sorts and organizes hand-drawn feather sketches by name.
Feather Surface SOP converts feather primitives to polygon surfaces.
Feather Surface Blend makes a feather follow the curvature of a polygon mesh.
Feather Template Interpolate SOP blends between different feather shapes. This is of particular relevance in grooms with very few feather types.
Feather Template from Shape SOP creates a feather object from curves and lets change provides fundamental adjustments for barbs and shaft.
Feather Uncondense SOP expands the virtual barbs on feather curves to real curve primitives.
Feather Utility SOP provides a collection of helpful functions for working with feather curves.
Feather Visualize SOP lets you change the visualization of feathers in the viewport.
Feather Width SOP sets the curve widths of feather shaft and barbs.

Groom nodes ¶

Guide Groom SOP now provides a Feathers section for drawing and planting feathers.
Some operators on the Guide Process SOP now have advanced settings that let you choose, whether you want to work on virtual barbs or barb curves. You also have options for working on a feather’s left and right barbs independently.

Content library examples ¶

	Download the Eagle Feathers files on the Content Library for the signature Houdini 20 eagle. There are two main files: `eagle_feathercreation.hip` shows the creation and placement of base feathers, and `eagle_render.hip` is where the various caches of feather patches are assembled and brought into LOPs for rendering in Karma XPU or CPU. There are also cameras and lights included.
	Download the Splashscreen Feathers file on the Content Library for the scene using the new feather tools to create the Houdini 20 splash screen image.