From Alex:

I realized that glyphs on slices are broken both in 3D view and in
slice views, they do not show up at all.

I traced the 3D display problem to your changes in revision 20910

What happens is that
vtkMRMLModelDisplayableManager::IsModelDisplayable() checks display
nodes for InputPolyData,
but vtkMRMLDiffusionTensorVolumeSliceDisplayNode has no input polydata
since it generates it internally.

The same may be true for other display nodes I guess.

I have not figure out why the 2D display does not work, I am not sure
what mechanism it uses these days. But could you take a look at 3D
display issue?

Thanks,
Alex

I fixed some issues here:
https://github.com/finetjul/Slicer/tree/2374-glyph-slice-display-node

However the glyph slice in 3D view still doesn't have a LUT correctly applied nor has its position correct.

As those commits are substantial, I would like a review/green light to push into trunk.

Julien: Looking at the code, the code seems to be limited to the "glyphable" nodes. That said, we should first check that tutorials and demo involving DTI work as expected.
Also thank you for adding comments into the code, that makes the review way easier :)

Alex: Could you take care of this ?

Reassigned to Julien since he is looking at it.

From what I've seen, the glyphs are black because the normals are inverted.
I believe, it's link with the fact that the entire slice has the wrong location in the 3D view.
So the slice transform might be wrong. I can't think of why the polydata redesign could have impacted that part.

Assigned back to Alex.

I don't see any changes in the code, and I don't see any glyphs displayed.
Not sure why JC re-assigned to me. Sending back to Julien.

The issue has been re-assigned to you because Julien mentioned that it has very probably nothing to do with the polydata re-design he introduced. Would be appreciated if you could you investigate further. Would that be possible ? Thanks

Alex: Did you try the following topic: https://github.com/finetjul/Slicer/tree/2374-glyph-slice-display-node ?

At the end it appeared that I made a mistake in the redesign.
So https://github.com/finetjul/Slicer/tree/2374-glyph-slice-display-node now contains the fix for 0002374.

Please review and let me know when it is safe to push on Slicer trunk.

Julien> Seems the three last commits associated with https://github.com/finetjul/Slicer/commits/2374-glyph-slice-display-node are 8 days old. Does this topic include your most recent work ?

Yes, I rewrote the history (squashed some commit with git rebase -i) and for some reason it kept the old date.

I am testing the functionality, but one issue I found so far:

• controls on Glyphs on Slices Display panel do not update glyphs immediately in 2D and 3D views. They get updated on interacting with the views.

Another issue:

1. switch between FA and Color by Orientation in Glyphs on Slices Display panel
2. rotate in 3D view to cause update (see previous note).
3. The glyphs turn RED in 3D view (incorrect)
4. Zoom or pan in 2D view: glyphs become correct color in both views.

One more:
Scalar Range in the Glyphs on Slices Display panel is greyed out.

I have finished testing of Julien's branch.
I tested mostly glyphs on slices, models, hierarchies, transforms and slices. I have not found any issues except for 3 that I reported above. I suggest committing the changes

Julien> Before committing, do you know what could be done to ensure the renderer is updated when expected ? Do you think it could be related to http://na-mic.org/Mantis/view.php?id=1536#c7231

For reference: After talking with Julien, he will provide a working patch by tomorrow 10am.

Fixed in r21427, r21428, r21429 and r21430