Instructions

For a simple static rendering of a 2D scene with a single image

Ignore the blender stuff. From the fly_view directory, simple run the script as:

python ./fly_view_stereo.py --image=IMAGE_FILENAME --output=OUTPUT_FILENAME(must be .png)

if you intend to render more than a single image, save the ommap's with command: --save-ommap=DIRECTORY_WHERE_TO_SAVE

then, next time, add the command: --ommap=DIRECTORY_WHERE_OMMAPS_SAVED

Introduction

The scripts in this package use blender, a free open source 3D modelling program, to render fly-view stills and movies. It is a bit roundabout and inelegant, but it works. The code uses blender to render the scene from two cameras for every desired point along a trajectory. These images are then converted to fly-view images. The entire process does take quite some time.

Much of the code is thanks to Dr. Andrew Straw, and based on the measurements made by Buchner (1971).

Download and setup blender

1. Download blender: http://www.blender.org/
2. Consider learning some of the basics
3. Open blender, and in the upper right corner of the main window, right click and drag left to create a second window
4. In the bottom left corner of that new window, click on the small 3D cube icon, and select "python console" from the pop up list

Creating the scene in blender

1. Enter the following at the python command prompt, which assigns the correct file to the variable filename:

   filename = "~/PathToGeneratorScript.py"

   For example, where PATH is the path to the FlyView directory:

   filename = "PATH/examples/create_arena_in_blender.py"

2. Execute the filename:

   exec(compile(open(filename).read(), filename, 'exec'))

3. Explore the scene in the left window

Creating the stereo camera in blender, and rendering a trajectory

1. Enter the following at the python command prompt, where PATH is the path to the FlyView directory

   filename = "PATH/blender/create_wideangle_camera_stereo.py"

2. Execute the file, this creates the object "stereocamera," which is associated with two 180 degree cameras:

   exec(compile(open(filename).read(), filename, 'exec'))

3. Run the following code in the command prompt, where "filename" is the filename of your desired trajectory (see below for format), and "destination" is the path to a (empty) directory where you wish to have the images saved

   stereocamera.render_trajectory(filename, destination)

   For example, to run the example trajectory and save the images run the following, where PATH is the path to the FlyView directory:

   filename = "PATH/examples/example_trajectory.csv"
   destination = "PATH/examples/rectilinear"
   stereocamera.render_trajectory(filename, destination)

   This will run a script that moves the stereocamera through the scene to each of the specified points, takes two images, and saves them to disk. Additionally, intrinsic camera matrices for the stereocamera will be saved to the same directory.

4. You can now close blender

Trajectory file format

The file describing the trajectory should be a simple comma seperated value file that follows the following convention: x_position, y_position, z_position, heading_in_radians

Rendering the Fly-View from the rectilinear images

Installing the flyview package (optional)

If you have not yet installed the flyview package, you can do so by running the following from within the FlyView directory:

python ./setup.py

Rendering a flyview trajectory for the first time, this takes a while

From inside the FlyView/flyview directory, run:

python ./fly_view_stereo.py --directory=PATH_TO_IMAGES_FROM_BLENDER --destination=PATH_TO_EMPTY_DIRECTORY_TO_SAVE_FLYVIEW_IMAGES --mat=INTRINSIC_CAMERA_MATRIX --save-ommap=PATH_WHERE_TO_SAVE_CALIBRATION_FOR_FUTURE_USE

For example, where PATH is the path to the FlyView directory:

python ./fly_view_stereo.py --directory="PATH/examples/rectilinear" --destination="PATH/examples/flyview" --mat="PATH/examples/rectilinear/intrinsic_camera_matrix_left.csv" --save-ommap="PATH/examples/rectilinear"

Rendering a flyview trajectory given a pre-existing calibration, this is much faster, but still takes time

python ./fly_view_stereo.py --directory=PATH_TO_IMAGES_FROM_BLENDER --destination=PATH_TO_EMPTY_DIRECTORY_TO_SAVE_FLYVIEW_IMAGES --ommap=PATH_TO_DIRECTORY_WHERE_OMMAP_CAN_BE_FOUND

Note, ommap points to the directory where ommap_left.pickle and ommap_right.pickle can be found, not the actual file(s)