Peak representation improvements

[guaje]

This PR is a redesign of the current peak_slicer actor. The design of the actor is heavily inspired in #374.

It includes the following features:

• A simplified creation method based on the simple geometry of the actor.
• New colors function.
• Added a vertex shader function that calculates the color given the orientation.
• Identification of global opacity.
• Added Look Up Colormap support.
• New class with attributes and methods suited for this specific actor.
• Shaders functions to control the visible peaks. Peaks in a range or peaks in selected slices, as shown in these videos.

Range	Planes
peak_range.mp4	peak_planes.mp4

[pep8speaks]

Hello @guaje! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2021-07-28 15:43:08 UTC

[codecov]

Codecov Report

Merging #433 (757b400) into master (d498b6d) will increase coverage by 0.53%.
The diff coverage is 94.22%.

@@            Coverage Diff             @@
##           master     #433      +/-   ##
==========================================
+ Coverage   88.32%   88.85%   +0.53%     
==========================================
  Files          31       33       +2     
  Lines        6448     6973     +525     
  Branches      770      822      +52     
==========================================
+ Hits         5695     6196     +501     
- Misses        534      546      +12     
- Partials      219      231      +12     

Impacted Files	Coverage Δ
fury/actors/peak.py	90.00% <90.00%> (ø)
fury/actor.py	89.18% <95.45%> (+0.13%)	⬆️
fury/actors/tests/test_peak.py	97.95% <97.95%> (ø)
fury/ui/tests/test_helpers.py	100.00% <0.00%> (ø)
fury/ui/tests/test_core.py	96.51% <0.00%> (+0.38%)	⬆️
fury/ui/containers.py	83.81% <0.00%> (+1.56%)	⬆️
fury/ui/helpers.py	98.21% <0.00%> (+5.35%)	⬆️

[skoudoro]

Hi @guaje,

here a quick review. I need to try your PR and go more into details.

Thank you for this feature

[guaje]

@Garyfallidis I ran some profiling tests here and these are the results:

For a 56x72x56 image the operation is adding less than 2 seconds (0:00:01.707887) to the for loop. Also, these are the average time and standard deviation of the operation: Avg = 0:00:00.000017, Std = 0:00:00.000006.

I don't think this is adding a significant delay in the peaks creation, but if you think something else needs to be done, please let me know.

[Garyfallidis]

That image is quite small. You should try it with something much larger. Will merge this PR now. But to run the same test with a much larger image. For example, the superresolved HYDI data.

[guaje]

I ran the same test on an HCP 7T subject's peaks with a size of 176x207x173 and these are the results: The operation is adding less than 20 seconds (0:00:19.486101) to the for loop. The average time and standard deviation were similar to the ones obtained with the smaller image.

Additionally, I ran a comparison test between the for loop of the current implementation of the peak slicer and the proposed version and found out that the peaks creation time of the new actor was around 20 minutes (0:03:31.901080) faster than the current version (0:24:02.964906).

[Garyfallidis]

Thanks @guaje. Merging.
In some of the docstrings you write (N, 3) array or ndarray. Just say array. Please make that fix in another PR.