Commands

ACISIN command in AutoCAD : Imports an ACIS (SAT) file and creates 3D solid, body, or region objects

Introduction — quick overview

If you need to bring an ACIS (.sat) 3D model into AutoCAD, the ACISIN command lets you import geometry and create editable 3D solids, bodies, or regions in your drawing. This guide explains what ACISIN does, gives clear step‑by‑step instructions, shows common problems and fixes, lists alternative import methods, and provides practical tips to get reliable results.

What is the ACISIN command?

ACISIN is an AutoCAD command that imports an ACIS (.sat) file and attempts to convert the geometry into AutoCAD-native objects (typically 3D solids, bodies, or regions). ACIS is a widely used CAD geometry kernel and the .sat file is a common neutral exchange format for 3D models.

Key points:

  • Supported file type: .sat (ACIS).
  • Output: 3D solids, surface bodies, or regions, depending on the geometry and import options.
  • Use case: Bringing 3D parts or assemblies from other CAD tools into AutoCAD for editing, documentation, or drafting.

How to use the ACISIN command (Step by step)

Below are clear, beginner-friendly steps to import an ACIS (.sat) file into AutoCAD.

  1. Preparation

    • Save a backup of your DWG before importing.
    • Set the drawing units to match the SAT file (UNITS command) to avoid scale problems.
    • Switch to a 3D workspace (e.g., 3D Basics or 3D Modeling) to simplify 3D tools and viewports.

  2. Launch the command

    • Type ACISIN in the command line and press Enter.
    • (Shortcut: typing ACISIN is the direct shortcut — some AutoCAD versions also allow using the generic IMPORT command.)

  3. Select the file

    • In the file dialog, browse and select the .sat file to import, then click Open.

  4. Choose import options (if prompted)

    • AutoCAD may offer options such as converting to solids, surfaces, or regions, depending on the file contents. Choose Solids if you plan to edit as solids.
    • If there are unit or scale prompts, confirm the correct units.

  5. Inspect the result

    • Use 3DORBIT, VIEWCUBE, or standard view commands to inspect the imported geometry.
    • Move the model to a dedicated layer if needed and freeze unneeded layers.

  6. Fix or convert geometry (if necessary)

    • If the import created surfaces or bodies rather than solids, try conversion tools (see the “Convert and repair” tips below).
    • Run AUDIT and PURGE to clean the drawing.

Example workflow:

  • UNITS → set units
  • ACISIN → select file → choose Solids
  • 3DORBIT → check model
  • AUDIT → fix errors
  • Save DWG

Options and common ACISIN behaviors

  • ACISIN typically converts closed ACIS shells into 3D solids. Open surfaces may import as surface objects or bodies.
  • Some versions of AutoCAD will prompt for conversion choices. If not, the import follows default behavior (usually creating solids when possible).
  • If the SAT file contains many separate parts, they may import as a collection of solids or grouped objects. Use EXPLODE or BURST with care.

Why ACISIN sometimes doesn’t work (common causes & fixes)

  1. Unsupported or newer ACIS version

    • Symptom: Import fails with an error about unsupported SAT version.
    • Fixes:
      • Ask the sender to export to an older ACIS version compatible with your AutoCAD.
      • Use an intermediate CAD tool (e.g., Rhino, Fusion 360, SolidWorks, or a version converter) to re-export a compatible SAT.

  2. Corrupt or incomplete SAT file

    • Symptom: Command aborts or imports incomplete geometry.
    • Fixes:
      • Request a fresh export from the source CAD.
      • Try opening the SAT in another application (Rhino/Inventor) to verify and re-export.

  3. Unit/scale mismatch

    • Symptom: Model appears extremely large/small or off the expected coordinates.
    • Fixes:
      • Set drawing units (UNITS) before import or rescale after import.
      • Ask source to confirm units on export.

  4. Extremely complex geometry or huge file

    • Symptom: Import takes a long time, AutoCAD slows, or import fails.
    • Fixes:
      • Break the source into smaller pieces and import separately.
      • Increase system resources or use a more capable CAD tool to simplify the model and re-export.

  5. Imported as surfaces instead of solids

    • Symptom: You get surfaces or regions that cannot be edited as solids.
    • Fixes:
      • Use conversion and repair tools (see next section).
      • If surfaces are open, try to close gaps in the source model before export.

  6. Missing ACIS engine or licensing issue

    • Symptom: Error referencing ACIS or import engines (rare).
    • Fixes:
      • Update AutoCAD to the latest service pack or reinstall if the installation is corrupted.

Convert, repair and edit imported geometry

After import you may need to convert or repair geometry to work with it as solids.

  • Check for open edges:
    • Use the EDGE display or visually inspect areas; open edges prevent creation of solids.
  • Common AutoCAD commands and actions:
    • UNION — combine multiple solids when they share faces.
    • SHELL / THICKEN — give thickness to surface shells (if available for your object type).
    • REGION — create regions from closed planar curves and then use EXTRUDE or PRESSPULL.
    • CONVTOSOLID (when available) — convert certain objects into solids.
    • SOLIDEDIT — advanced solid editing operations.
    • SLICE / TRIM — remove unwanted parts.
    • Run AUDIT to detect and fix drawing errors; run OVERKILL to clean duplicates.

If conversion in AutoCAD is not possible or reliable:

  • Open the SAT in a surfacing-capable tool (Rhino, Fusion 360, Inventor) for repair, then re-export as a compatible SAT or STEP file.

Alternative methods to import ACIS or 3D models

  • IMPORT command (AutoCAD): The generic IMPORT command can open or import many formats (including SAT in many versions).
  • OPEN: Some AutoCAD releases allow opening an SAT directly via File > Open.
  • Use another CAD tool as an intermediary:
    • Rhino, Fusion 360, Inventor, SolidWorks — open SAT, repair/convert, and re-export (SAT/STEP/IGES) compatible with your AutoCAD.
  • Use neutral formats:
    • If SAT gives trouble, ask for STEP (.stp/.step) or IGES (.igs), which may import more robustly into some systems.
  • Export as mesh (STL) only when you do not need editable solids — meshes are lighter but less editable as solids.

Practical tips for reliable imports

  • Always keep a backup of the DWG before importing.
  • Match units (UNITS) before importing to avoid scale issues.
  • Work on a separate layer for imported geometry to isolate and manage visibility.
  • If import time is long, close other applications and temporarily disable heavy visual styles.
  • If multiple parts import grouped, use EXPLODE cautiously to access individual solids.
  • Keep AutoCAD updated (service packs) to ensure compatibility with newer ACIS versions.
  • When collaborating, agree on a standard exchange format (ACIS version, STEP, or IGES) to minimize issues.

FAQ

What file types does the ACISIN command support?

ACISIN is designed specifically for ACIS (.sat) files. To import other formats, use AutoCAD’s IMPORT command or other conversion workflows (STEP, IGES, STL, etc.).

Why does AutoCAD report an “unsupported SAT version”?

This means the SAT file was created with a newer ACIS kernel than your AutoCAD supports. Solution: ask the source to export an older SAT version or re-export the model from an intermediate CAD application to a compatible SAT version.

I imported a model but it came in as surfaces — how do I turn them into solids?

If surfaces form a closed shell, use conversion tools like CONVTOSOLID, THICKEN, or create regions and extrude where appropriate. If surfaces have gaps, repair them in a surfacing tool (Rhino/Fusion) and re-export.

Can I import very large assemblies with ACISIN?

You can, but performance may degrade. For large assemblies, import parts separately, simplify geometry before export, or use tools designed to handle large assemblies (Inventor, Navisworks) and then bring only necessary geometry into AutoCAD.

Does ACISIN preserve layers and colors from the source file?

Layer and color preservation depends on how the SAT was exported. SAT is primarily geometric; layering and metadata may not transfer reliably. Expect to assign layers and properties in AutoCAD after import.

What should I do if ACISIN crashes or freezes AutoCAD?

Try these steps:

  • Open a fresh DWG and attempt import there.
  • Import a smaller part of the model (if available).
  • Update AutoCAD to the latest patches.
  • Use another CAD application to open and re-export the file in a different neutral format (STEP/IGES).

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