Point Cloud Renderer
What Makes Your Academic Paper/Report Beautiful! This is a demo/utility script use to render a point cloud, with integrated mitsuba2 python API. Here are some comparisons following (compare visualizations only, these are all nice work):
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Preparation
Tested version:
- Misuba >= 2.0.0
- Python 3.7
python dependency:
- argparse
- numpy
- pythonlib
- matplotlib
Please follow this guid to install misuba
and make sure it is installed before further step.
Quick Demo
source YOUR_PATH_TO_MITSUBA2/setpath.sh
python point_render.py -f chair_pcl.npy
than a image file named output.jpg
can be found in current fold:
It appears to contain a lot of noise. you can specify a larger sample times to smooth, but it will take more time to render:
python point_render.py -f chair_pcl.npy -s 256
Getting Started
All you need to do is provide a point cloud in .npy
form with shape [num_pts,3 coords(+3 colors(+1 size))]
, generated from numpy, and run this script. Here are some tips:
-
-f
to specify the path to your points file. -
-o
to specify the output filename of the render result. -
-s
to specify the sampling time for sampler -
-x
to specify thexml
file to be render. This will ignore the-f
option. -
-c
to specify the color mapping. The given.npy
file contain no colors will be colored by thematplotlib.colors.Colormap
specified by this option, like'turbo'
. -
-v
to specify a specific mitsuba variant, default to "scalar_spectral".
How to modify this script
Preliminary
First of all, you should know something about how to describe a scene in mitsuba
. In fact, mitsuba
describe scene use xml
file. please refere here for details. Next I assume you already know some basics knowledge about it, i.e., scene
, intergrater
, sampler
, emitters
and shape
.
Rather than using xml
file, we use mitsuba's python interface directly to load object from python dict
. By this way, a more programmer way, we can easily operate objects rather than click down and up on GUI.
This only requires a few conversions betwee their, refering to here. Some examples of conversions are listed below:
-
A tag with "name" can be treated as a field:
<type name="a" value=b
=>"a":type(b)
. e.g:<float name="height" value="123"> <string name="height" value="123"> <tranform name="to_world"> <scale value="2, 1, -1" /> <translate value="-1, 3, 4"/> </transform> <rgb name="radiance" value="100,400,100"/>
=>
"height": 123 "height": "123" "to_world": ScalarTransform4f.translate([-1, 3, 4]) * ScalarTransform4f.scale([2, 2, -1]) "radiance": { "type": "rgb","value": [100, 400, 100]}
-
a tag with "type" is a plugin in mistuba:
<class type="a"> ... </class>
=>{ "type":"a",...}
. e.g:<shape type="sphere"> <float name="radius" value="10"/> </shape>
=>
{ # this brackets cannot be discarded. since obly a dict contain "type" key is treatde as a plugin. "type" : "sphere", "radius": 10 },
for more properties of plugins please refer this link.
To Modify
- to add other types of data like
mesh
, please refer functioncreate_objects
. - to move shadow, please refer function
create_ground
or remove it fromobjs = {"ground_plane": create_ground(), }
. - to adjust the camara view, please refer
camera
in functioncreate_environment
. - ...
Known Problems
- fail to use
gpu
variant for rendering, because aGPU out of memory
error occurred. - At the moment I don't know how to render a animation, maybe only remde frame by frame, since I am also new to
mitsuba
. If you get it, please feel free to let me know.
Acknowledge
This script deeply based onMitsuba2PointCloudRenderer and PointFlowRenderer and is an easy-to-use version.