Menderer is a simple OpenGL mesh renderer for batch rendering a 3D triangle mesh into a list of specified camera poses. It supports meshes in PLY (ascii or binary) format. While various shadings (e.g. Phong shading) are implemented, there is currently no support for texture/normal maps. The tool is written in C++ and can be executed as a standalone command line application.
If you find the Menderer source code useful in your research or project, please feel free to cite it as follows:
@misc{menderer,
title = {Menderer - Batch Mesh Renderer},
author = {Maier, Robert},
howpublished = "\url{https://github.com/robmaier/menderer}",
year={2019}
}
The code was mostly developed and tested on Ubuntu Linux, hence we only provide the build instructions for Ubuntu in the following. However, the code should also work on other platforms.
Please first clone the source code:
git clone https://github.com/robmaier/menderer.git
Menderer requires
CMake,
OpenCV 4,
Eigen,
CLI11,
GLEW,
GLFW3,
happly
as third-party dependencies.
While Eigen, CLI11 and GLFW3 are already contained in the third_party folder, the other dependencies can be installed directly from the default Ubuntu repositories:
sudo apt install cmake libopencv-dev libglew-dev
To compile the Menderer application, use the standard CMake approach:
mkdir build
cd build/
cmake .. -DCMAKE_BUILD_TYPE=Release
make -j6
In the following, we provide a simple usage example for the data in folder data/lion/.
First, an output folder output/ is created:
# go into data folder
cd ../data/lion/
# create output folder
mkdir output/
We render the mesh mesh.ply into a virtual camera, which is specified by the pinhole camera parameters in intrinsics.txt and the target pose in pose.txt:
../../build/bin/Menderer -c intrinsics.txt -t pose.txt -m mesh.ply -o output/
Please check the rendered output image output/render_000000-color.png.
Instead of having only a single target camera pose, it is also possible to render the mesh into a list of camera poses trajectory.txt (TUM RGB-D Benchmark trajectory format):
../../build/bin/Menderer -c intrinsics.txt -t trajectory.txt -m mesh.ply -o output/
Again, the output images render_xxxxxx-color.png are generated in the output/ subfolder.
In addition to the format above (intrinsics.txt and pose.txt/trajectory.txt) , we also support Intrinsic3D dataset folders.
We show an example for downloading and rendering the Intrinsic3D Tomb Statuary data in the following:
# go into data/ folder again
cd ../
# create folder for dataset
mkdir tomb
cd tomb/
# create output/ folder
mkdir output/
# download, extract and rename mesh
wget https://vision.in.tum.de/_media/data/datasets/intrinsic3d/tomb-statuary-intrinsic3d.zip
unzip tomb-statuary-intrinsic3d.zip
mv tomb-statuary-intrinsic3d.ply mesh.ply
# download, extract and rename rgbd (with intrinsics and poses)
wget https://vision.in.tum.de/_media/data/datasets/intrinsic3d/tomb-statuary-rgbd.zip
unzip tomb-statuary-rgbd.zip
mv tomb-statuary-rgbd rgbd
After preparing the dataset, we can batch-render the mesh into the provided input camera poses:
../../build/bin/Menderer -d rgbd/ -m mesh.ply -o output/
Since Menderer can only load meshes from .ply files, we recommend Meshlab for converting meshes in other formats (e.g. .obj, .wrl, etc.) to the .ply format.
There are various command line options for the Menderer application in order to adjust the renderings and output options.
Input parameters (mandatory):
-c,--camera Camera intrinsics filename (file must exist).
-t,--trajectory Camera trajectory file in TUM RGB-D benchmark format (file must exist).
-d,--dataset" Dataset folder in Intrinsic3D format (folder must exist).
Either both options -c and -t or just option -d must be specified.
-m,--mesh" Input mesh file (file must exist).
Output parameters (optional):
-o,--output Output folder (folder must exist and must be empty).
Output flags (optional, without arguments):
--save_depth_png Save rendered depth (.png files) in output folder.
(Divide by scale factor 5000.0 to get metric depth)
--save_depth_binary Save rendered depth (.bin files) in output folder.
--save_mesh Triangulate rendered depth and save generated mesh
as .ply file in output folder.
GUI flags (optional, without arguments):
--gui Show GUI for rendered color
--pause Pause after each frame (continue with any button/space)
Renderer parameters (optional):
--shader OpenGL rendering shader (options: "none",
"normals_phong" (default), "phong", "normals").
--color_r Mesh color (red channel).
--color_b Mesh color (blue channel).
--color_g Mesh color (green channel).
--bg_r Rendering background color (red channel).
--bg_b Rendering background color (blue channel).
--bg_g Rendering background color (green channel).
Renderer flags (optional, without arguments):
--lighting Enable lighting (default false).
--colored Enable mesh colors (default false).
--flat Enable flat rendering (default false, i.e. smooth).
The following command line options demonstrate the use of implemented rendering modes:
1) Phong shading with normals as surface colors (default):
--shader phong_normals
2) Phong shading with uniform (gray) surface colors:
--shader phong --color_r 0.5 --color_g 0.5 --color_b 0.5
3) Render vertex colors without geometry/lighting:
--shader none --colored
4) Render normals (without Phong shading and geometry/lighting):
--shader normals
When the --save_depth_binary flag is specified, the binary depth images render_xxxxxx-depth.bin are additionally generated in the output/ subfolder.
The following code snippet shows how to load a binary depth map in Matlab (assumed the rendering resolution is 640x480).
% read file into matrix A
fileID = fopen('out_0.bin');
A = fread(fileID,[640, 480],'float');
fclose(fileID);
% permute dimensions (account for row-major/column-major)
A = permute(A,[2 1]);
% convert A to grayscale image
I = mat2gray(A);
% show image
imshow(I);
The Menderer source code is licensed under the GNU General Public License Version 3 (GPLv3), please see the LICENSE file for details.
If you have any questions, please contact Robert Maier <robert.maier@tum.de>.