Stitching Hemicube Renders into Fisheye or Spherical

hemicube-to-domemaster-visualizeSource of hemicube render – Source of idea for explanation

Stitching hemicube renders into fisheye
So you’ve rendered a scene from a 3D animation software and used a hemicube camera. Now you’re left with 2k footage from each of the 5 cameras: top, left, right, front, and back. But now what? Well you need to stitch the hemicube renders into a domemaster (fisheye).

But lets be clear from the start. Typically when someone says stitching, they mean that there is some automatic algorithmic analysis of how to best combine the footage. But in this instance we simply mean that we are specifically placing footage on the dome and having the dome distortion compensated for. Just like the image above.

There are several fulldome plugins for After Effects that make this process quite simple: Navegar FulldomeSky-Skan DomeXF, or Digistar Virtual Projector. I’ll be using the Navegar Fulldome Plugin in this tutorial.

AfterEffects-Screenshot-hemicube-to-domemasterDump all your footage into After Effects and give each hemicube render its own layer in the same comp (example image to the right). Then apply the fulldome plugin to all the layers and change the settings below for each hemicube layer (leave everything else to default).

Left (East)
— Altitude: 0
— Azimuth: 90
— Angular Width/Height: 90

Right (West)
— Altitude: 0
— Azimuth: -90
— Angular Width/Height: 90

Front (South)
— Altitude: 0
— Azimuth: 180
— Angular Width/Height: 90

Back (North)
— Altitude: 0
— Azimuth: 0
— Angular Width/Height: 90

Top (Zenith)
— Altitude: 90
— Azimuth: 0
— Rotation: 180 (may not be needed)
— Angular Width/Height: 90

Bug: Scale Needs Reset
Sometimes the scale says it’s showing 100%, but it actually isn’t functioning correctly. You can reset it by setting the angular width to 0, clicking away, and then setting it back to 90. This happens often enough that it’s apart of my workflow. You’ll know if it’s happening if all the hemicube renders look too small.

Seeing More than 180°
Once you have everything assembled, you can actually change with the spherical angle to see more of the scene. It’s typically at 180° to give you a perfect fisheye, but often it’s helpful to compress more like 200° into the dome. This allows you to actually see the nearby ground. It’s a powerful technique that doesn’t bring any noticeable distortion and actually enhances immersion. As you can see below, this extra 20° made all the difference for seeing the lakes of Titan. It doesn’t look like much here but on the dome it’s dramatic.


Other Stitching Software
Don’t have After Effects? Here are some alternative options for stitching.
— Glom (Spitz)
PineappleWare Stitcher
Domemaster Photoshop Actions Pack
— Domemaster (Linux)
— Hugin
Nuke (The Foundry) – Spherical Transform Node
Fusion (BlackMagic Design) – Cubemap to Equirectangular
Autopano Video (Kolor)

Stitching hemicube renders into spherical


With the same technique as discussed above, stitching together hemicube renders into the equirectangular projection (spherical) is quite simple.

Here are the only differences. They need to be set for each hemicube layer,
— Spherical Angle: 360
— Master Projection: Cylindrical Equidistant

Feel free to examine the After Effects scene from which the screenshot above was taken. Just be aware that you must have the Navegar Fulldome Plugin for it to function properly.

after effects scene / required: navegar fulldome plugin

3 thoughts on “Stitching Hemicube Renders into Fisheye or Spherical

  1. Pingback: Orbital Mechanics in the Satosphere | ewerx

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