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README.md
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@ -6,16 +6,24 @@
Description
===========
Draco is a library for compressing and decompressing 3D geometric [meshes] and [point clouds] intended to improve the storage and transmission of 3D graphics.
Draco is a library for compressing and decompressing 3D geometric [meshes] and
[point clouds]. It is intended to improve the storage and transmission of 3D
graphics.
Draco was designed and built for compression efficiency and speed. The code
supports compressing points, connectivity information, texture coordinates,
color information, normals, and any other generic attributes associated with geometry. With Draco, applications using 3D graphics can be significantly smaller without compromising visual fidelity. For users this means apps can now be downloaded faster, 3D graphics in the browser can load quicker, and VR and AR scenes can now be transmitted with a fraction of the bandwidth and rendered quickly.
color information, normals, and any other generic attributes associated with
geometry. With Draco, applications using 3D graphics can be significantly
smaller without compromising visual fidelity. For users, this means apps can
now be downloaded faster, 3D graphics in the browser can load quicker, and VR
and AR scenes can now be transmitted with a fraction of the bandwidth and
rendered quickly.
Draco is released as C++ source code that can be used to compress 3D graphics as well as C++ and Javascript decoders for the encoded data.
Draco is released as C++ source code that can be used to compress 3D graphics
as well as C++ and Javascript decoders for the encoded data.
**Contents**
_**Contents**_
* [Building](#building)
* [CMake Basics](#cmake-basics)
@ -39,32 +47,32 @@ Draco is released as C++ source code that can be used to compress 3D graphics as
Building
========
For all the platforms first you need to generate the project files, then you
need to compile the examples.
For all platforms, you must first generate the project/make files and then
compile the examples.
CMake Basics
------------
To generate project/make files for the default toolchain on your system simply
run `cmake` in the root of the Draco repo:
To generate project/make files for the default toolchain on your system, run
`cmake` in the root of your clone Draco repository:
~~~~~ bash
cmake .
~~~~~
On Windows the above command will produce Visual Studio project files for the
newest Visual Studio detected on the system. On Mac OS X and Linux systems, the
above command will produce a makefile.
On Windows, the above command will produce Visual Studio project files for the
newest Visual Studio detected on the system. On Mac OS X and Linux systems,
the above command will produce a `makefile`.
To control what types of projects are generated the `-G` parameter is added to
the `cmake` command line. This argument must be followed by the name of a
generator. Running `cmake` with the `--help` argument will list the available
To control what types of projects are generated, add the `-G` parameter to the
`cmake` command. This argument must be followed by the name of a generator.
Running `cmake` with the `--help` argument will list the available
generators for your system.
Mac OS X
---------
On Mac OS X you would run the following command to generate Xcode projects:
On Mac OS X, run the following command to generate Xcode projects:
~~~~~ bash
cmake . -G Xcode
@ -90,9 +98,9 @@ cmake . "Visual Studio 14 2015 Win64"
CMake Makefiles: Debugging and Optimization
-------------------------------------------
Unlike Visual Studio and Xcode projects, the build configuration for make builds
is controlled when you run `cmake`. The following examples demonstrate various
build configurations.
Unlike Visual Studio and Xcode projects, the build configuration for make
builds is controlled when you run `cmake`. The following examples demonstrate
various build configurations.
Omitting the build type produces makefiles that use build flags containing
neither optimization nor debug flags:
@ -122,9 +130,9 @@ cmake . -DCMAKE_BUILD_TYPE=debug
Android Studio Project Integration
----------------------------------
To include Draco in an existing or new Android Studio project it simply needs
to be referenced from the `cmake` file of an existing native project that has a
minimum SDK version of 18 or higher. To add Draco to your project:
To include Draco in an existing or new Android Studio project, reference it
from the `cmake` file of an existing native project that has a minimum SDK
version of 18 or higher. To add Draco to your project:
1. Add the following somewhere within the `CMakeLists.txt` for your project
before the `add_library()` for your project's native-lib:
@ -138,9 +146,10 @@ minimum SDK version of 18 or higher. To add Draco to your project:
include_directories("${CMAKE_BINARY_DIR}" /path/to/draco)
~~~~~
2. Add the library target "draco" to the `target_link_libraries()` call for your
project's native-lib. The `target_link_libraries()` call for an empty
activity native project looks like this after the addition of Draco:
2. Add the library target "draco" to the `target_link_libraries()` call for
your project's native-lib. The `target_link_libraries()` call for an
empty activity native project looks like this after the addition of
Draco:
~~~~~ cmake
target_link_libraries( # Specifies the target library.
@ -160,15 +169,15 @@ Usage
Command Line Applications
------------------------
The default target create from the build files will be the draco_encoder and
draco_decoder command line applications. For both applications if you run them
without any arguments or `-h`, the applications will output the usage and
The default target created from the build files will be the `draco_encoder`
and `draco_decoder` command line applications. For both applications, if you
run them without any arguments or `-h`, the applications will output usage and
options.
Encoding Tool
-------------
`draco_encoder` will read OBJ or PLY files as input and output Draco encoded
`draco_encoder` will read OBJ or PLY files as input, and output Draco-encoded
files. We have included Stanford's [Bunny] mesh for testing. The basic command
line looks like this:
@ -176,7 +185,8 @@ line looks like this:
./draco_encoder -i testdata/bun_zipper.ply -o out.drc
~~~~~
A value of `0` for the quantization parameters will not perform any quantization on the specified attribute. Any value other than `0` will quantize the input values for the specified attribute to that number of bits. For example:
A value of `0` for the quantization parameter will not perform any quantization on the specified attribute. Any value other than `0` will quantize the input values for the specified attribute to that number of bits.
For example:
~~~~~ bash
./draco_encoder -i testdata/bun_zipper.ply -o out.drc -qp 14
@ -184,20 +194,21 @@ A value of `0` for the quantization parameters will not perform any quantization
will quantize the positions to 14 bits (default for the position coordinates).
In general the more you quantize your attributes the better compression rate
you will get. It is up to your project on how much deviation it will tolerate.
In general most projects can set quantizations values of about 14 without any
noticeable difference in quality.
In general, the more you quantize your attributes the better compression rate
you will get. It is up to your project to decide how much deviation it will
tolerate. In general, most projects can set quantizations values of about `14`
without any noticeable difference in quality.
The compression level parameter turns on/off different compression features.
The compression level (`-cl`) parameter turns on/off different compression
features.
~~~~~ bash
./draco_encoder -i testdata/bun_zipper.ply -o out.drc -cl 8
~~~~~
In general the highest setting, 10, will have the most compression but
worst decompression speed. And 0 will have the least compression, but best
decompression speed. The default setting is 5.
In general, the highest setting, `10`, will have the most compression but
worst decompression speed. `0` will have the least compression, but best
decompression speed. The default setting is `5`.
Encoding Point Clouds
---------------------
@ -219,8 +230,8 @@ and denser point clouds.
Decoding Tool
-------------
`draco_decoder` will read Draco files as input and output OBJ or PLY files. The
basic command line looks like this:
`draco_decoder` will read Draco files as input, and output OBJ or PLY files.
The basic command line looks like this:
~~~~~ bash
./draco_decoder -i in.drc -o out.obj
@ -229,7 +240,11 @@ basic command line looks like this:
C++ Decoder API
-------------
If you’d like to add decoding to your applications you will need to include the draco_dec library. In order to use the Draco decoder you need to initialize a DecoderBuffer with the compressed data. Then call DecodeMeshFromBuffer() to return a decoded Mesh object or call DecodePointCloudFromBuffer() to return a decoded PointCloud object. E.g.
If you'd like to add decoding to your applications you will need to include
the `draco_dec` library. In order to use the Draco decoder you need to initialize a `DecoderBuffer` with the compressed data. Then call
`DecodeMeshFromBuffer()` to return a decoded mesh object or call
`DecodePointCloudFromBuffer()` to return a decoded `PointCloud` object. For
example:
~~~~~ cpp
draco::DecoderBuffer buffer;
@ -244,17 +259,18 @@ const draco::EncodedGeometryType geom_type =
}
~~~~~
Please see 'mesh/mesh.h' for the full Mesh class interface and 'point_cloud/point_cloud.h' for the full PointCloud class interface.
Please see `mesh/mesh.h` for the full Mesh class interface and `point_cloud/point_cloud.h` for the full `PointCloud` class interface.
Javascript Decoder
------------------
The Javascript decoder is located in `javascript/draco_decoder.js`. The
Javascript decoder can decode mesh and point cloud. In order to use the
decoder you must first create `DecoderBuffer` and `WebIDLWrapper` objects. Set the
encoded data in the `DecoderBuffer`. Then call `GetEncodedGeometryType()` to identify
the type of geometry, e.g. mesh or point cloud. Then call either `DecodeMeshFromBuffer()` or
`DecodePointCloudFromBuffer()` which will return a Mesh object or a point cloud. E.g.
decoder you must first create `DecoderBuffer` and `WebIDLWrapper` objects. Set
the encoded data in the `DecoderBuffer`. Then call `GetEncodedGeometryType()`
to identify the type of geometry, e.g. mesh or point cloud. Then call either
`DecodeMeshFromBuffer()` or `DecodePointCloudFromBuffer()`, which will return
a Mesh object or a point cloud. For example:
~~~~~ js
var buffer = new Module.DecoderBuffer();
@ -282,13 +298,14 @@ Javascript Decoder Performance
The Javascript decoder is built with dynamic memory. This will let the decoder
work with all of the compressed data. But this option is not the fastest.
Pre-allocating the memory sees about a 2x decoder speed improvement. If you
know all of your project's memory requirements you can turn on static memory
know all of your project's memory requirements, you can turn on static memory
by changing `Makefile.emcc` and running `make -f Makefile.emcc`.
three.js Renderer Example
-------------------------
Here's an [example] of a geometric compressed with Draco loaded via a Javascript decoder using the three.js renderer.
Here's an [example] of a geometric compressed with Draco loaded via a
Javascript decoder using the `three.js` renderer.
Please see the `javascript/example/README` file for more information.
@ -299,15 +316,22 @@ For questions/comments please email <draco-3d-discuss@googlegroups.com>
If you have found an error in this library, please file an issue at <https://github.com/google/draco/issues>
Patches are encouraged, and may be submitted by forking this project and submitting a pull request through GitHub. See [CONTRIBUTING] for more detail.
Patches are encouraged, and may be submitted by forking this project and
submitting a pull request through GitHub. See [CONTRIBUTING] for more detail.
License
=======
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
Licensed under the Apache License, Version 2.0 (the "License"); you may not
use this file except in compliance with the License. You may obtain a copy of
the License at
<http://www.apache.org/licenses/LICENSE-2.0>
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
License for the specific language governing permissions and limitations under
the License.
References
==========