SketchUp

Fix SketchUp Dynamic Component Scale Bug When Copying

Posted on by Nguyen Huu Khanh
Fix Dynamic Scale Tool
23
Aug

SketchUp Dynamic Components are powerful — until you copy one and watch everything break. The scale attribute crash is one of the most persistent bugs in SketchUp, still reproducible in SketchUp 2026: copy a Dynamic Component with Move + Ctrl (or paste from clipboard), try to scale it, and the child objects freeze at the original parent’s dimensions — or worse, collapse to zero. The root cause is attribute inheritance: child objects inside a copied Dynamic Component continue reading parameters from the original parent’s definition rather than the new instance. The values in the Component Options dialog turn red, the geometry refuses to respond, and no amount of re-entering numbers fixes it unless you force a formula re-evaluation. Groups inside Dynamic Components make this dramatically worse. Unlike Components, Groups do not carry their own definition copy, so when you nest a Group inside a Dynamic Component and copy that parent, the Group’s attributes stay hard-linked to the original. Renaming the Group does not sever that link — only converting it to a Component before adding formulas will give it a clean, independent attribute copy that survives duplication. A second, lesser-known trigger is that SketchUp only fires a formula recalculation when you interact with the Scale tool directly on that instance. A copy made without triggering the Scale tool is never asked to recalculate, so its children hold the parent’s hard-coded dimensions indefinitely. This is why right-clicking and choosing Scale Definition, or nudging any value in Component Options, sometimes appears to “magically” repair a copy — it manually fires the recalc the copy never received. The Fix Dynamic Scale tool inside the Parashape SketchUp plugin automates exactly that repair: it forces the selected instance to re-evaluate all its formulas and rewrite child geometry to the correct computed dimensions, without requiring you to explode, rebuild, or restart SketchUp.

Key Features

  • One-click formula re-evaluation. Selecting a broken Dynamic Component copy and clicking the Fix Dynamic Scale icon triggers a full re-evaluation pass on every formula in that instance. All child dimensions, positions, and visibility states recompute from the instance’s own attribute values rather than the original’s, clearing the red-value state in Component Options in a single action.
  • Batch repair across multiple selected instances. You can select several broken Dynamic Component copies at once before running the tool. All instances are repaired in a single pass, which is critical when you have arrayed copies of a component along a path or scattered across a scene — repairing them one by one risks re-linking a fixed copy to a still-broken neighbor.
  • Handles glued component scale reset. Glued components (those placed on a face with Glue To: Any) have an additional failure mode: their scale resets to 1,1,1 when the host face is scaled or the component is moved to a new face. The fix tool detects glued components and re-applies the stored attribute-driven dimensions after repositioning, so the visual result matches what Component Options shows.
  • Nested Group detection and warning. When the tool encounters a Dynamic Component that contains nested Groups (the primary cause of persistent scale bugs), it flags those Groups in the Ruby Console and suggests converting them to Components. This surfaces the authoring problem rather than silently papering over it, so the fix holds after the next copy operation instead of requiring the tool every time.
  • Works without exploding or rebuilding. Traditional workarounds — explode the broken copy, rebuild from scratch, or make it unique and re-enter all values — destroy the component’s identity and history. The Fix Dynamic Scale tool repairs in place: the component remains the same definition, retains its placement, and keeps any material or layer assignments intact.
  • Compatible with SketchUp 2022 through 2026. The underlying bug exists across all recent SketchUp versions. The tool targets the SketchUp Ruby API’s Sketchup::ComponentInstance#definition and dynamic_attributes hash, which have been stable across that version range, so the same fix works regardless of which year’s release you are on.

How to Install and Use

  1. Install Parashape. The Fix Dynamic Scale tool is part of the Parashape SketchUp plugin. Download the free version from the Parashape page and install the .rbz file via SketchUp’s Extension Manager (Window → Extension Manager → Install Extension). Restart SketchUp after installation to load the toolbar.
  2. Sign in with your 3dshouse account. Open the Parashape toolbar (View → Toolbars → Parashape). The toolbar will show a Sign In button if you are not yet authenticated. Click it, complete the browser-based login, and the toolbar icons become active. The fix tool is available on the free tier — no Pro subscription is required.
  3. Reproduce the scale bug to confirm it is present. Make a copy of any Dynamic Component using Move + Ctrl or Edit → Paste. Try scaling the copy with the Scale tool. If child geometry refuses to resize correctly, or Component Options shows values in red, the instance is broken and ready to repair.
  4. Select the broken Dynamic Component copy (or copies). Click once on the broken instance to select it. To repair multiple broken copies at once, use a selection box or Ctrl + click to add more instances to the selection. You do not need to enter the component for editing — top-level selection is sufficient.
  5. Click the Fix Dynamic Scale icon in the Parashape toolbar. The icon shows a component with a wrench overlay. The tool runs immediately — there is no dialog. Watch the Component Options panel: the red values should turn black and the geometry should snap to the correct dimensions within one second.
  6. Verify in Component Options. Open Component Options (Window → Component Options) for the repaired instance. All attribute values should display in black text, and the geometry should match what those values describe. If a value is still red, the attribute formula references a parameter that does not exist in this instance’s definition — that is an authoring error in the original DC that the fix tool cannot resolve without the source formula being corrected.
  7. Convert nested Groups to Components if the bug recurs. If copying the repaired component immediately breaks the new copy again, open the original definition (double-click to enter), select any Groups inside, right-click → Make Component, add the DC attributes to the new component, and update the parent formulas to reference the new component’s attribute names. After that, copies will no longer inherit the original’s Group attributes.

Pro Tips

  • Author with Components, never Groups, inside any DC that will be copied. This is the single most effective way to avoid the scale bug entirely. Every element that will carry a formula — width, height, position offset, visibility — must be a Component instance with its own definition. Groups look convenient because they do not create a new definition entry in the Components panel, but that convenience is exactly what causes the attribute leak when you copy the parent. The rule of thumb: if an object inside a DC has an _scale_tool_used or dimension formula, it must be a Component.
  • Use Make Unique before editing a copy you want to diverge. If you copy a Dynamic Component and then want to give that copy different attribute values from the original, right-click it and choose Make Unique before changing anything in Component Options. Without Make Unique, both instances share the same definition — editing one changes the other. More importantly, Make Unique gives the copy its own definition copy, which is what the Fix Dynamic Scale tool re-evaluates against.
  • Right-click → Scale Definition as a quick diagnostic before running the tool. Right-clicking a Dynamic Component and choosing Scale Definition forces SketchUp to resize the definition bounding box to fit the current geometry. This often clears a visual scale mismatch without a plugin. If Scale Definition fixes the visual but Component Options still shows red values, then run Fix Dynamic Scale to repair the attribute layer. The two operations complement each other.
  • Nudge Component Options values to force a recalc without the plugin. If you do not have the tool installed and need a quick fix: open Component Options for the broken copy, find any numeric attribute, increment it by a small amount (e.g., add 0.001 to the width), press Enter, then undo the change. That sequence triggers SketchUp’s formula evaluator for that instance. It is fiddly and unreliable for complex DCs with many children, but it works for simple two- or three-attribute components when you are on a machine where the plugin is not installed.
  • Check _scale_tool_used when building DCs for distribution. SketchUp writes a hidden attribute _scale_tool_used to a component instance when the user scales it with the Scale tool. Some DC formulas read this flag to decide whether to recompute. If your formula chain depends on this flag but the end-user copies instead of scales, the flag is never set and the chain never fires. Design formulas that do not gate on _scale_tool_used, or explicitly set it in your copy-paste workflow before distributing the file.

System Requirements

  • SketchUp version: SketchUp 2022 or newer (2022, 2023, 2024, 2025, 2026)
  • Operating system: Windows 10/11 or macOS 12 Monterey and newer
  • Plugin: Parashape SketchUp plugin (free tier, 3dshouse account required for login)
  • Dynamic Components extension: Must be enabled in SketchUp (included by default; check Extension Manager if Component Options is missing from the Window menu)
Nguyen Huu Khanh

Architect turned developer