Command line application for converting OpenSimulator OAR files into GLTF scene file.
An OpenSimulator OAR file saves a region's contents. All the information about the region (parcels, terrain, etc.) is saved in an OAR file along with all the objects and their locations (prims, meshes, scripts, textures, etc.). Thus, an OAR file of a region is convertable into any other scene representation format.
Convoar reads an OAR file and outputs a GLTF scene and image files which is most of the region information. Most specifically, it outputs the textured mesh representation of all the objects in the region.
Convoar is evolving.
See the "Releases and Roadmap" section below.
The current version reads an OAR file and outputs either an unoptimized GLTF
scene file or a "material reorganized" GLTF scene (see below).
The output GLTF is not packed or binary
so the output files are a JSON .gltf file, one or more .buf files
(containing the vertex information), and an images directory with
the texture files for the mesh materials. By default, the output textures
are either JPG or PNG format depending if there is any transparency
in the texture.
The unoptimized GLTF conversion is a simple conversion of the OAR primitives which creates many, many meshes and is very inefficient for rendering but is good for editing (importing into Blender, for instance).
The "material reorganized" scene has objects corresponding to each unique material (texture/color/features) and the meshes have been assigned to each of these material objects. This renders the scene uneditable but this should greatly reduce the number of draw calls needed to render the scene in OpenGL/WebGL.
Future versions of convoar with either contain or have tools to perform other optimizations to the scene and the object therein.
The name "convoar" is from "convert oar" and is pronounced like "condor". There is a logo idea in there somewhere.
Checkout the convoar sources and run the prebuilt binary in the dist directory.
The binaries are compiled for .NET Framework 4.6 so you must install that
library version better on Windows10 or, if running on Linux, Mono v4.2.1
or better.
git clone https://github.com/Misterblue/convoar
if Windows:
convoar/dist/convoar.exe region.oar
if Linux:
mono convoar/dist/convoar.exe region.oarThe full invocation form is:
convoar <parameters> inputOARfile
A short list of the available parameters (a boolean parameter can be followed with
a true or false):
| Parameter | Meaning |
|---|---|
--mergeSharedMaterialMeshes or -m |
reorganize all meshes in the scene into groups using the same materials. This makes the scene uneditable but will make for way fewer draw calls when displayed. |
--outputdir or -d |
directory for generated GLTF and image files. Default is `./convoar'. |
--regionName |
Name to use for generated scene. Default is name of input OAR file. |
--textureMaxSize |
Maximum size for textures. All images are resized to less than this dimension. Default is 256. |
--halfRezTerrain |
Whether to reduce terrain resolution by two. Default is true. |
--createTerrainSplat |
whether to create a terrain texture based on height. Default is true. |
--verbose or -v |
Output information on numbers of meshes, etc. |
--help |
list all available parameters with descriptions and default values |
An invocation of convoar ../REGION.oar will create, in the output directory,
the files REGION.gltf, one or more REGION-bufferNNN.buf files, and an
images directory containing .JPG and .PNG files. The GLTF file will reference
the images directory and the .buffiles so the relative directory position of the.buf and images files is significant.
The output directory is changed with the --outputdir parameter.
Convoar uses OpenSimulator sources to do the reading and conversion of the OAR file. These source files are included in this repository. So there is a simple build where one just builds the sources checked out, and there is the updating build where one fetches new versions of the OpenSimulator sources.
Some functionality has been moved out into another project that must be
checked out in the same directory as Convoar. Checkout HerbalCommonEntitiesCS
into the same directory as the Convoar project. This will include
CommonEntities and CommonEntitiesUtil.
Under windows 10, use Visual Studio 2017 or better. At the moment, convoar is
built under Windows to create the dist directory.
The prebuilt binaries will run on Windows10 and with Mono on Linux.
There are no external dependencies --
everything is included in the Convoar GitHub repository.
If compiling on Linux, one needs Mono version 5 or better and one
just uses msbuild.
To update the OpenSimulator sources, the script gatherLibs.sh fetches the
required DLLs from other repositories. The other repositories must be cloned
into the same directory as the convoar repository so the steps could be:
git clone https://github.com/Misterblue/convoar.git
git clone https://github.com/Herbal3d/HerbalCommonEntitiesCS.git
git clone git://opensimulator.org/git/opensim
(build OpenSimulator)
git clone https://github.com/Misterblue/libopenmetaverse.git
(build libOpenMetaverse)
cd convoar
./gatherLibs.sh
Then convoar can be built using either Visual Studio or msbuild.
For those with Docker environments, there is a Docker image of convoar.
Assume the OAR to be converted is at /tmp/frog/REGION.oar.
Then, to do the conversion:
docker pull herbal3d/convoar
docker run --rm --user $(id -u):$(id -g) -v /tmp/frog:/oar herbal3d/convoar REGION.oarThis maps the local /tmp/frog directory to the /oar directory in
the Docker container, runs the container, and writes the output GLTF files
into the /tmp/frog directory.
NOTE: the most common problem is permissions. The command above, sets the
user and group IDs to that of the current user (the --user parameter)
which is usually is the right thing for write permissions into the mapped directory.
Convoar reads in the totality of the OAR file and then maps the various features of the scene into the GLTF definition. This mapping is incomplete. What follows is a list of features that are copied:
- Scene
- Primitives: converted to a mesh using PrimMesher using highest LOD setting
- Sculptie: converted into a mesh using PrimMesher using highest LOD setting
- Mesh: repackaged as a mesh. Mesh vertices and indices are deduplicated and repacked for GPU efficiency
- Linksets: All meshes in a linkset are grouped into a GLTF group of meshes
- Images: All images are converted into JPEG or PNG. PNG is used if there is any transparency in the image. The images are all resized to be less than
TextureMaxSizeon a side (default is 256); - Materials: mesh face info is converted into a material and the following attributes are copied:
- face image
- face color (RGBA)
- transparency
- bump
- glow
- shiny
- two sided (parameter
DoubleSided. Default isfalse)
- Terrain: A mesh is created from the region heightmap. The mesh resolution is in meters (so a standard sized region would be 256x256 vertices) but a half size mesh (parameter
HalfRezTerraindefault istrue) can be generated
- Release 1.0
- basic OAR to GLTF conversion
- material-centric optimization
- Release 1.1
- cleaned up and debugged command line and Docker version
- Release 1.2
- bug release -- trying to figure out why some JPEG2000 don't decomopress.
- Release 1.3 and after
- bug releases and optimization experimentation before going to version 2
- Release 2.0
- option to include all prim information in
extras(scripts, notes, etc.) - pipeline tools in Docker image for binary/DRACO packing of GLTF file
- invocation options to select sub-regions of OAR region
- option to include all prim information in
- Release 2.1
- pipeline tools for scene optimizations (small mesh elimination, mesh decimation/simplification, etc.)