First test rendering with Delaunay.
Fix frustum orientation.
viewer: initial test on blending with mesh
viewer: use left-right key to pan the camera
Add image vertices.
Enable blending with the last image.
viewer: bring back sideway control
Add options to show/hide grid and thumbnails.
Remove old red sphere code.
Use ShaderMaterial for both Delaunay and plane rendering.
Preload texture of images at 1 move distance WIP.
Viewer: add turning keys.
Viewer: add modes.

Now mouse is disabled on walking mode. ESC goes to orbit mode.
Viewer: preload images, not textures.
Viewer: add navigation buttons.
Viewer: tweaks to make it work on a small window.
viewer: read initial image in URL.

Use a hash like #file=path/to/file&img=INITIAL_IMAGE_ID
Viewer: get focus on click.
Update readme with new url format.
Viewer: test drifting symmetrically.