From 997375493fe0842967aa199263c8ff7b9917c0fa Mon Sep 17 00:00:00 2001
From: Mark Hale <mark.hale@physics.org>
Date: Tue, 7 Mar 2017 23:04:09 +0000
Subject: [PATCH] VR videos.

Signed-off-by: Mark Hale <mark.hale@physics.org>
Former-commit-id: 7e14c54ae7696ac75aa54201674b6fa5c8a0801c
---
 contrib/blender/README.md    | 17 +++++++++++++
 contrib/blender/odm_video.py | 46 +++++++++++++++++++++++++++++++-----
 2 files changed, 57 insertions(+), 6 deletions(-)

diff --git a/contrib/blender/README.md b/contrib/blender/README.md
index 6c92f74f..74b93008 100644
--- a/contrib/blender/README.md
+++ b/contrib/blender/README.md
@@ -22,3 +22,20 @@ To generate a 360 3D panoramic photo:
 Output is `<project-path>/odm_photo/odm_photo_vr_L.jpg` and `<project-path>/odm_photo/odm_photo_vr_R.jpg`.
 
 **NB: argument order matters!**
+
+# odm_video
+Renders videos from ODM generated texture models.
+Currently can produce 360 panoramic videos.
+NB: the default resolution is 4096x2048 (maximum supported by Facebook).
+
+## Requirements
+* Blender
+* Python 2.7 (must be on your PATH)
+* Spatial Media Metadata Injector (https://github.com/google/spatial-media/tree/master/spatialmedia) (place in `spatialmedia` subdirectory)
+
+## Usage
+To generate a 360 panoramic photo:
+
+    blender -b photo_360.blend --python odm_video.py -- <project-path> <camera-waypoints.xyz> <number-of-frames>
+
+Output is `<project-path>/odm_video/odm_video_360.mp4`.
diff --git a/contrib/blender/odm_video.py b/contrib/blender/odm_video.py
index 47469f51..6faf8b15 100644
--- a/contrib/blender/odm_video.py
+++ b/contrib/blender/odm_video.py
@@ -5,8 +5,9 @@
 # blender -b photo_360.blend --python odm_video.py -- <project-path> <camera-waypoints.xyz> <number-of-frames>
 
 import sys
-import bpy
 import subprocess
+import os
+import bpy
 from common import loadMesh
 
 
@@ -30,6 +31,7 @@ def main():
     # create path thru waypoints
     curve = bpy.data.curves.new(name='CameraPath', type='CURVE')
     curve.dimensions = '3D'
+    curve.twist_mode = 'Z_UP'
     nurbs = curve.splines.new('NURBS')
     nurbs.points.add(numWaypoints-1)
     weight = 1
@@ -52,18 +54,37 @@ def main():
     followPath.use_curve_follow = True
     animateContext = bpy.context.copy()
     animateContext['constraint'] = followPath
-    bpy.ops.constraint.followpath_path_animate(animateContext, constraint='CameraFollowPath')
+    bpy.ops.constraint.followpath_path_animate(animateContext,
+                                               constraint='CameraFollowPath',
+                                               frame_start=0,
+                                               length=numFrames)
 
     blendName = bpy.path.display_name_from_filepath(bpy.data.filepath)
     fileName = projectHome + '/odm_video/odm_' + blendName.replace('photo', 'video')
     scene.frame_start = 0
-    scene.frame_end = numFrames - 1
+    scene.frame_end = numFrames
     render = scene.render
-    render.filepath = fileName
+    render.filepath = fileName + '.mp4'
+    render.image_settings.file_format = 'FFMPEG'
+    if(render.use_multiview):
+        render.image_settings.stereo_3d_format.display_mode = 'TOPBOTTOM'
+        render.image_settings.views_format = 'STEREO_3D'
+        render.views[0].file_suffix = ''
+        format3d = 'top-bottom'
+    else:
+        width = render.resolution_x
+        height = render.resolution_y
+        format3d = 'none'
     render.resolution_x = 4096
     render.resolution_y = 2048
-    render.image_settings.file_format = 'FFMPEG'
-    #bpy.ops.render.render(animation=True)
+
+    render.ffmpeg.audio_codec = 'AAC'
+    render.ffmpeg.codec = 'H264'
+    render.ffmpeg.format = 'MPEG4'
+    render.ffmpeg.video_bitrate = 45000
+    bpy.ops.render.render(animation=True)
+
+    writeMetadata(fileName+'.mp4', format3d)
 
 
 def loadWaypoints(filename):
@@ -75,5 +96,18 @@ def loadWaypoints(filename):
     return waypoints
 
 
+def writeMetadata(filename, format3d):
+    subprocess.run(['python',
+                    'spatialmedia',
+                    '-i',
+                    '--stereo='+format3d,
+                    filename,
+                    filename+'.injected'])
+    # check metadata injector was succesful
+    if os.path.exists(filename+'.injected'):
+        os.remove(filename)
+        os.rename(filename+'.injected', filename)
+
+
 if __name__ == '__main__':
     main()