Migration of old pieces

Coordinate Transformation

During the consolidation of the seamless system into seamless v2 the coordinate system was changed. The x-Axis runs along the default viewing direction of the listener. The coordinate systems were normalized

Automatic

For pieces composed for the EN325 or the HuFo his can be done using the reascripts in this repo.

  1. open reaper-session of the piece that should be rotated (best to do it in a copy) on a computer with both the old and the new seamless client installed

  2. load the reascripts (Actions->Show Action List->New Action->Load ReaScript)

  3. open the script migrate_seamless_plugins.lua for editing

  4. set the value for scaling_factor to \(6.046\) for the EN325 or to \(12.108\) if its a HuFo piece

  5. set rotate to false for the EN325 or to true for the HuFo

  6. run the script

  7. if each source track has both plugins on it and the transformed automation lanes exist (and were opened) this was a success. yay!

  8. run delete_old_plugins.lua, you can probably guess what it does

  9. Yay! Yippee

Manual

1. rotation of the coordinate system

For Pieces for the H0104 or HuFo first rotate the coordinate system:

\[\begin{split}x_\text{rotated} = - y_\text{old}\\ y_\text{rotated} = x_\text{old}\end{split}\]

2. move coordinate origin (H0104 only)

\[\begin{split}x_\text{offset} = 12.9246\\ y_\text{offset} = 0.0855\end{split}\]

then move the coordinate origin:

\[\begin{split}x_{\text{recentered}} = x_{\text{rotated}} + x_\text{offset} \\ y_{\text{recentered}} = y_{\text{rotated}} + y_\text{offset}\end{split}\]

3. apply scaling

Scaling factor $S$

\[\begin{split}S_{\text{H0104}} = 25.4492 \\ S_{\text{EN325}} = 6.046 \\ S_{\text{HUFO}} = 12.108\end{split}\]
\[\begin{split}x_\text{scaled} = x_\text{recentered}/{S}\\ y_\text{scaled} = y_\text{recentered}/{S}\\ z_\text{scaled} = z/{S}\end{split}\]

4. Apply flip of axis (H0104 only)

flip y axis

\[y_\text{flipped} = -y_\text{scaled}\]

change channel routing

There is only one 3rd order ambisonics decoder now, so the output channels have to be adjusted:

  • 1st order ambi: channel 33-36

  • 3rd order ambi: channel 33-48

  • omni: channel 33

  • lfe: channel 50

The SeamLess source channels (1-32) stay the same.