rhino3d-scripts

# Rhino 3D Scripting Skill Write production-quality scripts for Rhinoceros 3D. Covers the three scripting surfaces (RhinoScript/VBScript, RhinoPython, direct RhinoCommon .NET) and the Rhino 8+ Script Editor. ## When to Use This Skill - User asks to write, edit, or debug a `.rvb`, `.vbs`, or `.py` Rhino script - User wants a Rhino **command macro** or wants to automate a sequence of Rhino commands - User wants to manipulate geometry, layers, blocks, materials, viewports, or annotations from code - User mentions `rhinoscriptsyntax`, `scriptcontext`, `RhinoCommon`, `Rhino.Geometry`, `RhinoDoc`, or the Script Editor - User wants to pick objects, prompt for input, or build a small UI inside Rhino - User asks how to load, run, or distribute a script (startup scripts, aliases, toolbar buttons) ## Choosing a Scripting Surface Pick the surface based on the task, not preference. Recommend Python by default for new work. | Surface | When to choose | File ext | |---|---|---| | **RhinoPython** (`rhinoscriptsyntax` + RhinoCommon) | Default for new scripts. Best ecosystem, readable, full RhinoCommon access. | `.py` | | **RhinoScript** (VBScript) | Maintaining legacy `.rvb`/`.vbs` files; integrating with VBA/COM. | `.rvb`, `.vbs` | | **RhinoCommon (C#/.NET) via Script Editor** | Performance-critical loops, complex geometry, leveraging .NET libraries. | `.cs` | | **Command macro** | Pure sequence of existing Rhino commands; no logic. | toolbar/alias | A macro is **not** a script — it is a string of command-line input (e.g. `! _-Line 0,0,0 10,0,0 _Enter`). Use a script the moment you need a variable, loop, or conditional. ## Prerequisites - Rhino 7 or later (Rhino 8 strongly recommended — unified Script Editor supports Python 3, VB, and C# in one window). - Script Editor: type `_ScriptEditor` (Rhino 8) or `_EditPythonScript` / `_EditScript` (older). - Run a saved file from the command line with `_-RunPythonScript` or `_LoadScript` + `_RunScript`. ## Core Patterns ### Python: minimal scaffold ```python import rhinoscriptsyntax as rs import scriptcontext as sc import Rhino def main(): obj_id = rs.GetObject("Select a curve", filter=rs.filter.curve, preselect=True) if not obj_id: return length = rs.CurveLength(obj_id) print("Length: {0:.4f}".format(length)) if __name__ == "__main__": main() ``` ### Python: working with RhinoCommon directly ```python import Rhino import scriptcontext as sc doc = sc.doc # Rhino.RhinoDoc.ActiveDoc tol = doc.ModelAbsoluteTolerance circle = Rhino.Geometry.Circle(Rhino.Geometry.Point3d(0, 0, 0), 5.0) curve_id = doc.Objects.AddCircle(circle) doc.Views.Redraw() ``` ### VBScript: minimal scaffold ```vbscript Option Explicit Call Main() Sub Main() Dim strObject strObject = Rhino.GetObject("Select a curve", 4) ' 4 = curve filter If IsNull(strObject) Then Exit Sub Rhino.Print "Length: " & Rhino.CurveLength(strObject) End Sub ``` ### Picking objects with a custom filter (Python, RhinoCommon) ```python import Rhino import scriptcontext as sc go = Rhino.Input.Custom.GetObject() go.SetCommandPrompt("Select breps") go.GeometryFilter = Rhino.DocObjects.ObjectType.Brep go.SubObjectSelect = False go.GetMultiple(1, 0) if go.CommandResult() != Rhino.Commands.Result.Success: pass else: ids = [go.Object(i).ObjectId for i in range(go.ObjectCount)] ``` ## Step-by-Step Workflows ### Bulk-modify many objects fast 1. Disable redraw: `rs.EnableRedraw(False)`. 2. Wrap mutations in a single undo record: `undo = doc.BeginUndoRecord("My Op")` … `doc.EndUndoRecord(undo)`. 3. Use RhinoCommon directly inside the loop (skip `rhinoscriptsyntax` overhead). 4. Re-enable redraw and call `doc.Views.Redraw()` in a `try`/`finally` so a crash never leaves the viewport frozen. ### Distribute a script to a teammate 1. Save the `.py` / `.rvb` somewhere on disk. 2. Add the folder to `Options → Files → Search paths` so Rhino can find it by name. 3. Create a toolbar button or alias whose macro is: - Python: `! _-RunPythonScript "MyScript.py"` - RhinoScript: `! _-LoadScript "MyScript.rvb" _-RunScript MySubName` 4. The leading `!` cancels any running command; `-` runs the command in script (no-dialog) mode. ### Run code at Rhino startup 1. Place a `.rvb`/`.py` in a search path. 2. `Tools → Options → RhinoScript` (or `Python`) → add to **Startup** list. The file executes once per session. ## Gotchas - **`rhinoscriptsyntax` returns GUIDs, RhinoCommon returns objects.** Mixing them is fine, but `doc.Objects.Find(guid)` is the bridge from a `rs.*` id to a `RhinoObject`. - **Coordinates differ by surface.** Python uses `(x, y, z)` tuples *or* `Rhino.Geometry.Point3d`; VBScript uses 3-element `Array(x, y, z)`. Never pass a Python list to a VBScript helper through COM. - **`Option Explicit` is off by default in VBScript.** Typos silently create new variables. Always add `Option Explicit` at the top of `.rvb` files. - **VBScript has no block scope.** All `Dim`s inside a `Sub` are hoisted to the top of the procedure. Loop counters leak. - **`Nothing`, `Empty`, and `Null` are different** in VBScript. Use `IsNull` for `Rhino.GetObject` failure, `IsEmpty` for uninitialized `Variant`, `Is Nothing` for object refs. - **Parentheses change calling semantics in VBScript.** `Call Foo(a, b)` and `Foo a, b` are valid; `Foo(a, b)` (no `Call`, with parens) is **not** a call to a Sub — it’s a syntax error for multi-arg subs and a forced `ByVal` for single-arg. - **Tolerance is per-document.** Always read `doc.ModelAbsoluteTolerance` rather than hardcoding `0.001`; users work in mm, m, inches, etc. - **Long loops should poll `Rhino.RhinoApp.EscapeKeyPressed`** so the user can cancel. Otherwise Rhino appears frozen. - **GUID strings vs `System.Guid`.** `rhinoscriptsyntax` accepts either; RhinoCommon wants `System.Guid`. Convert with `System.Guid(str_id)` if needed. - **Don’t call `doc.Views.Redraw()` inside a tight loop.** Toggle redraw once outside the loop. - **`.rvb` is just `.vbs` renamed** with a Rhino-specific extension so Rhino’s `LoadScript` recognizes it. Same VBScript engine. - **`Rhino.RhinoApp.IsHeadless` may not exist on older Rhino 8 builds.** Use `getattr(Rhino.RhinoApp, "IsHeadless", None)` and check for `None` before using. Fall back to a heuristic (e.g. `sc.doc.Views.Count == 0`) or assume GUI present. - **`RhinoMath` is at `Rhino.RhinoMath`, not `Rhino.DocObjects.RhinoMath`.** Accessing `Rhino.DocObjects.RhinoMath` raises `AttributeError`. - **`doc.Objects.AddBrep()` returns `System.Guid.Empty` on failure.** In Rhino 8 CPython the `System` namespace may not be directly importable; check the return value as a string: `str(obj_id) == "00000000-0000-0000-0000-000000000000"`. - **`rhinoscriptsyntax` has no type stubs.** Static analysers (Pylance/Pyright) flag `import rhinoscriptsyntax as rs` as unresolvable. Suppress with `# type: ignore` on the import line; the module is always available at Rhino runtime. - **Never name a script after a Python standard-library module** (e.g. `random.py`, `math.py`, `os.py`). IronPython 2.7 (`_-RunPythonScript`) resolves the script directory before stdlib, so any `import random` inside the stdlib (e.g. `tempfile` imports `random` internally) will find your file instead and fail with `Cannot import name <X>`. CPython 3 (`rhinocode`) is unaffected because it resolves stdlib first. Rename the script or avoid importing modules that pull in the shadowed name. - **Em dashes and other non-ASCII characters silently break `_-RunPythonScript` (IronPython 2.7).** `rhinocode script` uses CPython 3 (UTF-8 by default) so the same file works there, making the failure non-obvious. IronPython 2.7 raises `SyntaxError: Non-ASCII character '\xe2'` at the first offending byte. The most common culprit is the **em dash** (`--` auto-converted to `--` by many editors). Add `# -*- coding: utf-8 -*-` as line 1 of every script that must run under both runtimes, and replace typographic characters with ASCII equivalents: em dash `--`, arrow `->`, multiplication `x`. ## Troubleshooting | Symptom | Fix | |---|---| | `rs.GetObject` returns `None` immediately | The user pressed Escape, or your `filter` excludes everything. Re-check `rs.filter.*` flags. | | “Unable to find script” when running by name | The folder isn’t in `Options → Files → Search paths`. | | VBScript `Type mismatch` on coordinates | You passed a 2-element array. Rhino requires 3-element `Array(x, y, z)`. | | Python `ImportError: No module named Rhino` | You’re running CPython outside Rhino. RhinoCommon is only available in Rhino’s embedded Python (or via `rhino3dm` for read-only file work). | | Created geometry doesn’t appear | You forgot `doc.Views.Redraw()`, or `rs.EnableRedraw(False)` was never re-enabled. | | Undo undoes only the last object of a batch | Wrap the batch in `BeginUndoRecord` / `EndUndoRecord`. | | Script works alone but fails as a startup script | Startup runs before any document is open — return early or skip document-dependent work when `sc.doc is None`. | | `rs.Command("...")` returns `False` | The macro string is malformed. Prefix with `!` and `-`, end every prompt with `_Enter` or a value. | | `AttributeError: type object 'RhinoApp' has no attribute 'IsHeadless'` | Property added in a later Rhino 8 build. Use `getattr(Rhino.RhinoApp, "IsHeadless", None)` and guard against `None`. | | `rhinocode script` ignores arguments after the script path | rhinocode concatenates extra tokens onto the file URI. Pass data via a temp file or a Rhino dialog instead. See `references/macros-and-loading.md`. | | `Cannot import name <X>` inside stdlib (e.g. `tempfile`, `os`) when using `_-RunPythonScript` | Script filename shadows a stdlib module (e.g. `random.py` shadows `random`). IronPython 2.7 searches the script directory before stdlib. Rename the script, or remove the `import` that pulls in the shadowed module and replace it with a direct alternative (e.g. read `%TEMP%` via `os.environ` instead of `import tempfile`). | | `SyntaxError: Non-ASCII character '\xe2' ... but no encoding declared` | IronPython 2.7 (`_-RunPythonScript`) hit an em dash or similar character. Add `# -*- coding: utf-8 -*-` as line 1, or replace the character: em dash `--`, arrow `->`. The same file runs fine under `rhinocode` (CPython 3), which hides the problem. | ## References - [references/rhinoscriptsyntax-cheatsheet.md](references/rhinoscriptsyntax-cheatsheet.md) — most-used `rs.*` functions by category. - [references/rhinocommon-map.md](references/rhinocommon-map.md) — which namespace to import for which task. - [references/macros-and-loading.md](references/macros-and-loading.md) — command-line macro syntax, `LoadScript` / `RunScript`, search paths. - [references/vbscript-quirks.md](references/vbscript-quirks.md) — VBScript-only traps relevant to RhinoScript. ### Upstream docs - RhinoScript landing: <https://docs.mcneel.com/rhino/8/help/en-us/information/rhinoscripting.htm> - Developer hub: <https://developer.rhino3d.com/> - RhinoCommon API index: <https://mcneel.github.io/rhinocommon-api-docs/api/RhinoCommon/html/R_Project_RhinoCommon.htm> - Example scripts repo: <https://github.com/mcneel/rhino-developer-samples/tree/8/rhinoscript>