Saving A Mesh To Disk

Overview

  • The main output of SEQUOIA is a file on disk containing the resulting data from the meshing process.
  • Supported file formats include Thinkbox’ XMesh files, .OBJ files, .PLY files, .STL, .U3D, .PDF (3D PDF) and .FBX files.
  • There are three approaches to saving a mesh to disk:
  • Select the Mesher object to save and use the Main Menu > File > EXPORT Scene Data > Export Selected MESH In World/Object Space... menu item.
  • Select the Mesher object to save, expand the “Export” rollout and press the [Export UCS Space...] or [Export World Space...] button.
  • Select the Mesher object to save, expand the “Hacksaw” rollout, adjust the subdivision settings and press the [Export UCS Space...] or [Export World Space...] button to generate multiple XMesh files. See next topic for details.
  • In all cases, if the Mesher does not contain a valid mesh yet, it will be updated first, and then the resulting mesh will be saved to disk.
  • The resulting mesh can be loaded back into the same Document or into a different Document to check out the output using a Mesh Loader object.

Which Mesh Format To Use?

  • Each mesh format has its own benefits and drawbacks.
  • You should pick the format that has the most benefits and is supported by your target platform / software.
  • Within SEQUOIA, we recommend using XMesh exclusively.

XMesh

  • XMesh is a binary format which offers very good compression and supports all necessary channels.
  • Its drawback is that outside of SEQUOIA, it is currently supported only in Autodesk 3ds Max, Autodesk Maya and The Foundry’s NUKE.
  • The XMesh Loaders for these applications are free of charge and more are planned in the future.

OBJ

  • OBJ is an ASCII file format with no compression whatsoever and supports only a very small set of basic channels.
  • OBJ files written by SEQUOIA do not contain Vertex Color data.
  • Resulting files are huge and take long to save and load.
  • On the positive side, OBJ is supported by a very large number of applications, so it is the Least Common Denominator of geometry exchange.

PLY

  • PLY is binary and produces much smaller files than OBJ, but a bit larger than XMesh.
  • It is recommended as an alternative to OBJ when supported by the target platform due to its size and the fact that it supports Vertex Colors.

STL

  • STL was originally designed for providing data to 3D printers.
  • It is binary but uncompressed, so it is smaller than OBJ, but larger than XMesh and PLY.

U3D

  • The U3D file format is used by SEQUOIA mainly as an intermediate format to embed 3D content into a 3D PDF file.
  • The U3D format could be used separate from PDF to exchange data with another application that supports this format.
  • U3D is a scene description format and can contain additional data, for example texture map references.
  • U3D is not well compressed, and the export of very large meshes (hundreds of millions of polygons) can be memory-intensive, so is recommended only for simplified meshes.
  • Support for U3D export is available since SEQUOIA v1.1.
  • U3D import is currently not available.

3D PDF

  • A 3D PDF file can contain text and interactive 3D content in the same document.
  • It can be viewed and navigated using the Adobe Reader software.
  • This makes it great for sharing SEQUOIA output with users that do not have access to or knoweldge of 3D software.
  • Support for 3D PDF export is available since SEQUOIA v1.1.

FBX

  • The Autodesk FBX file format is supported by a very large number of 3D applications, making it very useful for mesh data interchange.
  • FBX is a scene description format, but at the moment SEQUOIA only exports and imports the first mesh object
  • FBX support is available since SEQUOIA v1.1.

Below is a comparison of the file sizes produced from a mesh with 10,688,904 faces and 5,332,944 vertices:

Format Size on Disk ZIP-Compressed Supported Channels
XMesh 165,111,621 bytes 164,011,784 bytes Vertices,Faces,Colors,Normals
FBX 234,056,544 bytes 226,277,851 bytes Vertices,Faces,Colors,Normals
PLY 282,945,621 bytes 149,171,608 bytes Vertices,Faces,Colors,Normals
U3D 448,612,096 bytes 119,390,394 bytes Vertices,Faces,Colors,Normals
STL 534,445,284 bytes 213,637,047 bytes Vertices,Faces,Colors
OBJ 893,220,732 bytes 176,765,153 bytes Vertices,Faces,Normals