Camera Pan Renderer

A simple script for rendering animations of .ply files with vertex-colors.

Installation

This script was designed to use bpy as a module, courtesy of this repo. The following install instructions provide how to do this. Alternatively, you may run the script using blender's python using blender --python render.py <input_folder> <output_folder>.

Installing bpy as a module

You may attempt pip install numpy future_fstrings bpy, but in my experience installing bpy in this way fails.

Instead, follow instructions from here [https://github.com/TylerGubala/blenderpy/releases/tag/v2.91a0]

  1. Install blender dependecies from https://wiki.blender.org/wiki/Building_Blender/Linux/Ubuntu
  2. Download the wheel distribution from https://github.com/TylerGubala/blenderpy/releases/tag/v2.91a0
  3. pip install bpy-2.91a0-cp37-cp37m-manylinux2014_x86_64.whl && bpy_post_install

Regardless of which method you used, once bpy is installed, run bpy_post_install in your terminal.

Setup

By default, for a given .ply with vertex colors, the script will:

1. Open up template.blend
2. Import your .ply at the origin
3. Set the material of your .ply to be a material named "vertex_color" (a material which already exists in the provided template.blend)
4. Rotate the ply by 90deg around the X axis (as specified by --override_ply_euler's default value)
5. Click 'Render Animation'

So, to make sure you will get sensible output, you should follow those steps yourself using an example PLY file, and make modifications to template.blend or any commandline arguments as necessary.

If you wish, you can affect the program behavior by modifying template.blend via the Blender UI, for example by:

• Editing the position / location / intensity of lights relative to your PLY file
• Editing the camera trajectory. Pro-tip: Select the curve, and search for "Convert To" and convert the Curve object to a Mesh. Edit it as a mesh using Proportional Editing, then use "Convert To" to turn it back into a camera curve. You may need to re-assign the cameras 'Follow' constraint to point at the curve again once editing is done.
• Changing the camera properties or render resolution

Running the script

python render.py <input_folder> <output_folder>, where input_folder contains a set of ply files to be rendered. For each .ply file in the input folder, the script will produce a folder of rendered frames in the output_folder. You may process these into a video as shown in these ffmpeg examples