chanfried / mayo

3D CAD viewer and converter based on Qt + OpenCascade

Mayo the opensource 3D CAD viewer and converter

👓 Overview

• Convert 3D files
  Mayo can read/write 3D files from/to STEP, IGES, STL and many other CAD formats

• Visualize 3D files
  Mayo 3D viewer supports clip planes, exploding of assemblies, measurement of shapes, show/hide parts, ...

• Cross platform
  Mayo runs on Windows, Linux and macOS

• Solid foundations
  Mayo is developed in modern C++ with Qt and OpenCascade

For more details have a look at this fine review Introducing Mayo by Libre Arts
There's also a complete video on YouTube

⚡ Features

• 3D clip planes with configurable capping

• 3D exploding of the model tree allowing better exploration of complex designs

• 3D measure tools for circles, angles, lengths, areas, bounding box, ...

• 3D view cube providing intuitive camera manipulation

• Quick access to CAD files recently open thanks to thumbnails in the Home page

• Toggle item visibility within the Model tree(use checkbox)

• Customizable mesh precision for BREP shapes, affecting visualization quality and conversion into mesh formats

• Convert files to multiple CAD formats from command-line interface💻

💾 Supported formats

Format	Import	Export	Notes
STEP	✅	✅	AP203, 214, 242
IGES	✅	✅	v5.3
BREP	✅	✅	OpenCascade format
DXF	✅	❌
OBJ	✅	✅
glTF	✅	✅	1.0, 2.0 and GLB
VRML	✅	✅	v2.0 UTF8
STL	✅	✅	ASCII/binary
AMF	✅	✅	v1.2 Text/ZIP(export)
PLY	✅	✅	ASCII/binary
OFF	✅	✅
3MF	✅	❌
3DS	✅	❌
FBX	✅	❌
Collada	✅	❌
X3D	✅	❌
Image	❌	✅	PNG, JPEG, ...

See also this dedicated wikipage for more details

🔍 3D viewer operations

Operation	Mouse/Keyboard controls
Rotate	mouseLeft + move
Pan	mouseRight + move
Zoom	mouseLeft + mouseRight + move
Zoom +/-	mouseWheel(scroll)
Window zoom	CTRL + mouseLeft + move
Instant zoom	spaceBar
Select Object	mouseLeft click
Select Objects	SHIFT + mouseLeft clicks

Mayo supports also multiple 3D viewer navigation styles to mimic common CAD applications(CATIA, SOLIDWORKS, ...)

📦 Install

Release packages are available for Windows and Linux on the Releases page.

Alternatives for Windows:

• Winget

winget install --id Fougue.Mayo

• Scoop

scoop bucket add extras
scoop install extras/mayo

🔨 How to build

Instructions for Windows
Instructions for Linux
Instructions for macOS

🎬 Gallery

Easy to use command-line utility for batch conversion of CAD files

Import of glTF file with textures

Import of STEP file with many parts

Import of PLY file defining point cloud

Options dialog with import/export configuration per CAD format

Home page with quick access to recent files