Plane analysis and turning form with value

Analyze surface planes and assign value steps that show how forms turn toward and away from light.

What it is

Plane analysis breaks a complex object into simple flat faces, or planes, that face different directions. A cheek may include front, three-quarter, side, top, and bottom planes, each receiving a different amount of light.

Turning form with value means assigning a value step to each plane based on its direction toward the light. You control transitions between planes by softening or sharpening them where needed.

A faceted pass blocks in chunky, planar values before refinement. You can soften selected transitions while keeping the plane structure, so the form reads as round and solid.

Why it matters

Plane analysis helps values move logically from one plane to the next. Weak control can make forms look mushy, inflated, dented, or sticker-like, while extra rendering adds noise without correcting the shape.

You can check it when

✓Draw simple planes over a photo or your own painting, and check whether the shading aligns with those planes.
✓Block in a head, figure, or prop with 3 to 5 value steps per side, without blending, and check whether it reads as solid and turning in space.
✓Check whether value changes follow the underlying form, such as the cheekbone to the side of the head or the top of the arm to its side.
✓Simplify a soft, organic object into plane groups before rendering, then check whether the final smooth shading retains that structure.

Plane analysis and turning form with value

What it is

Why it matters

You can check it when

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