Ward Material Node

Ward simulates a surface whose micro-facets are oriented in a preferred direction. The highlights then become stretched, perpendicular to that direction. This is exactly what happens with brushed aluminum: the horizontal grooves of the surface cause vertically stretched highlights.

Introduced by Gregory J. Ward (1992), this model is the standard for rendering anisotropic surfaces efficiently.

• Effects Library: Tools > 3D > Material > Ward
• Quick add: right-click in the Node Editor → Add Tool > 3D > Material > Ward

Visual comparison:

Isotropic shader (Blinn, Phong, standard Cook Torrance)

The highlight is a round disc. Uniform intensity in every direction around the point of maximum reflection. That is the expected behavior for smooth surfaces like plastic or polished metal.

Anisotropic shader (Ward)

The highlight is a line / elongated ellipse. Stretched either in the U direction (horizontal) or V (vertical) of the UV mapping. It simulates the micro-grooves of grooved surfaces.

Quick test: look at a brushed aluminum pan or a CD facing a lamp. The highlight is a stretched line, not a dot. That is anisotropy.

• Diffuse Material (orange) - base color and texture.
• Specular Color Material (green) - highlight tint. White for plastic/glass, the metal's color for metal.
• Specular Intensity Material (magenta) - intensity map (alpha).
• Spread U Material (white) - map controlling the horizontal falloff of the highlight.
• Spread V Material (white) - map controlling the vertical falloff of the highlight.
• Bump Map Material (white) - 3D material for apparent relief.

Ward → Shape 3D (MaterialInput) → Merge 3D → Renderer 3D

The orientation of the anisotropy depends on the object's UV mapping. To align the highlights in a precise direction, adjust the UVs with a UV Map 3D beforehand.

Diffuse section

• Color / Alpha / Opacity - same as Blinn/Phong.

Specular section

Specular Color

Highlight color. White for glass/plastic, tinted for metal.

Specular Intensity

Strength of the highlight.

Spread U (horizontal axis)

Falloff of the highlight in the U direction. Low = narrow highlight horizontally. High = wide highlight horizontally.

Spread V (vertical axis)

Same thing for the V direction.

Quick formula: low Spread U + high Spread V = a narrow vertical highlight (brushed horizontally). The opposite for vertical brushing.

Transmittance section

Same as the other shaders (Attenuation, Alpha/Color Detail, etc.).

• Brushed metal (aluminum, stainless steel) - dark gray Diffuse, metal-tinted Specular Color, low Spread U (0.1) / high Spread V (0.8). A vertically stretched highlight simulating horizontal grooves.
• Hair / fur - high Spread U + very low Spread V = highlights stretched in the direction of the strands. A classic for CG hair styling.
• Satin / velvet - satin fabrics have a subtle directional sheen. Set Spread U/V for a soft highlight in the direction of the weave.
• Vinyl / record - the concentric micro-grooves create a characteristic anisotropic highlight.
• Machined / turned surface - metal parts machined on a lathe keep circular marks that show up as anisotropy.
• CD / glowing disc effect - combined with a Reflect with chromatic aberration = the characteristic rainbow of a CD facing a light.

• U/V direction = UV direction - the orientation of the anisotropy depends on the object's UVs. The same Ward gives different results depending on the UV mapping. Use UV Map 3D to adjust the direction.
• Spread U ≠ Spread V, otherwise isotropic - if U and V are equal, the highlight becomes round again. You need an imbalance to see the anisotropy.
• Ward + Reflect for convincing brushed metal - the anisotropic highlight + environment reflections reduced by the roughness = a believable render.
• Performance - Ward is slower than Blinn/Phong but comparable to Cook Torrance. Reasonable for a hero object.
• Not for smooth metals - polished chrome is isotropic (round highlights). Use Cook Torrance + Reflect instead.
• For radial brushing (like on the side of an SSD hard drive), the UVs must be radial - a cylindrical or custom UV mapping is required.