What is ʼProjectʼ vs. ʼPullʼ a curve in Rhino?

ByCADbrief Staff

Short Answer

In Rhino 3D, Project pushes curves onto a surface or polysurface along the active construction plane’s normal, while Pull finds the closest points on the target surface and drapes the curve onto it. For most professional workflows, use Pull when you need the most accurate surface-following result. Limitation: Project can miss areas on steep or hidden geometry.

What You Need to Know Before

Warning: If your target surface has overhangs, trimmed areas, or complex curvature, Project and Pull can produce very different results from the same source curve. A common failure is assuming they are interchangeable, which often creates misaligned engraving, panel cuts, or inaccurate edge curves.

How to…

  • Command: Pull

  • Shortcut: No default shortcut

  • Quick Steps:

    1. Select the curve you want to place on the surface, then run Pull from the command line or search bar.
    2. When prompted, select the target surface or polysurface in the viewport.
    3. Press Enter to create the pulled curve, then verify the result in a shaded or wireframe view.

Variables & Settings

  • Key Setting: Target object type

  • Expert Setting: Pull works best when pulling onto a single clean surface or a well-joined polysurface. If you instead use Project, the projection direction depends on the active viewport/CPlane direction, so always confirm you are in the correct view before running the command.

Why it Fails

  • Cause 1 (Geometry): The source curve is too far from the target, or the surface shape causes multiple possible nearest locations, leading to unexpected Pull results.
  • Cause 2 (layers/Locks): The target surface is on a locked layer or is not selectable, so Rhino cannot complete the projection or pull operation correctly.
  • Cause 3 (Command/Logic): Project uses a direction-based result, not a closest-point result, so curves can land in the wrong place if the active view direction is not intended.

Quick Fix & Best Practice

  • Quick Fix: If a projected curve lands incorrectly, switch to the correct viewport and rerun Project, or use Pull instead when the curve must follow the surface accurately.
  • Manager’s Verdict: Use Project for fast direction-based layout work like panel lines or toolpath setup; use Pull for engraving, trimming references, and any workflow where the curve must truly sit on the surface.

FAQ

Is Pull more accurate than Project in Rhino?

Yes, for surface-following results, Pull is usually more accurate.

Does Project use the active view direction?

Yes, Project follows the active CPlane or viewport projection direction.

Can I use Pull on a polysurface?

Yes, Pull works on polysurfaces, but cleaner results usually come from simpler target geometry.

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