Modal (aka tripod) solver rework

Several major things are done in this commit:

- First of all, logic of modal solver was changed.
  We do not rely on only minimizer to take care of
  guessing rotation for frame, but we're using
  analytical rotation computation for point clouds
  to obtain initial rotation.

  Then this rotation is being refined using Ceres
  minimizer and now instead of minimizing average
  distance between points of point of two clouds,
  minimization of reprojection error of point
  cloud onto frame happens.

  This gives quite a bit of precision improvement.

- Second bigger improvement here is using bundle
  adjustment for a result of first step when we're
  only estimating rotation between neighbor images
  and reprojecting markers.

  This averages error across the image sequence
  avoiding error accumulation. Also, this will
  tweak bundles themselves a bit for better match.

- And last bigger improvement here is support of
  camera intrinsics refirenment.

  This allowed to significantly improve solution
  for real-life footage and results after such
  refining are much more usable than it were before.

Thanks to Keir for the help and code review.

1 files changed, 1 insertions, 2 deletions

diff --git a/release/scripts/startup/bl_ui/space_clip.py b/release/scripts/startup/bl_ui/space_clip.py
index e32db805a29..14fbbe15cfd 100644
--- a/release/scripts/startup/bl_ui/space_clip.py
+++ b/release/scripts/startup/bl_ui/space_clip.py
@@ -332,8 +332,7 @@ class CLIP_PT_tools_solve(CLIP_PT_tracking_panel, Panel):
         col.prop(tracking_object, "keyframe_b")
 
         col = layout.column(align=True)
-        col.active = (tracking_object.is_camera and
-                      not settings.use_tripod_solver)
+        col.active = tracking_object.is_camera
         col.label(text="Refine:")
         col.prop(settings, "refine_intrinsics", text="")