billboards using geometry shader

[m-agour]

This is an example on how a geometry shader can be used along with some minimal calculations to generate billboards using the dot actor.

https://user-images.githubusercontent.com/63170874/179493243-55b28d24-2c94-485d-af7e-ccb296733f34.mp4

[m-agour]

Hello @guaje, @filipinascimento , Thank you so much for your review. They are very helpful and insightful. After the animation api PR gets merged, I will try improve this and add these changes, it shouldn't take many time. Scale will have to be set. I didn't test color changing using utils.colors_from_actor and utils.update_actor functions should work fine and fast.

[guaje]

Hello @guaje, @filipinascimento , Thank you so much for your review. They are very helpful and insightful. After the animation api PR gets merged, I will try improve this and add these changes, it shouldn't take many time. Scale will have to be set. I didn't test color changing using utils.colors_from_actor and utils.update_actor functions should work fine and fast.

@m-agour for the scale, you can check how the primitive.repeat_primitive function works for the primitive.prim_square.

For color, I do agree there shouldn't be a problem, but testing such functions doesn't hurt either.

[pep8speaks]

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

• In the file docs/examples/viz_geom_billboard.py:

Line 108:26: E127 continuation line over-indented for visual indent

• In the file docs/tutorials/03_shaders/viz_billboard_sdf_spheres.py:

Line 61:1: E265 block comment should start with '# ' Line 64:1: E265 block comment should start with '# ' Line 70:1: E265 block comment should start with '# ' Line 73:1: E265 block comment should start with '# ' Line 82:1: E265 block comment should start with '# ' Line 85:1: E265 block comment should start with '# ' Line 94:1: E265 block comment should start with '# ' Line 97:1: E265 block comment should start with '# ' Line 113:1: E122 continuation line missing indentation or outdented Line 132:1: E265 block comment should start with '# ' Line 135:1: E265 block comment should start with '# ' Line 146:1: E122 continuation line missing indentation or outdented Line 163:1: E122 continuation line missing indentation or outdented Line 193:1: E265 block comment should start with '# '

• In the file fury/actor.py:

Line 1079:17: E131 continuation line unaligned for hanging indent Line 2809:41: E127 continuation line over-indented for visual indent

Comment last updated at 2022-09-02 14:43:41 UTC

[codecov[bot]]

Codecov Report

Merging #631 (0c0750f) into master (db9771c) will decrease coverage by 0.08%. The diff coverage is 0.00%.

:exclamation: Current head 0c0750f differs from pull request most recent head ae80544. Consider uploading reports for the commit ae80544 to get more accurate results

@@            Coverage Diff             @@
##           master     #631      +/-   ##
==========================================
- Coverage   50.40%   50.31%   -0.09%     
==========================================
  Files         120      120              
  Lines       26830    27026     +196     
  Branches     2972     2992      +20     
==========================================
+ Hits        13523    13598      +75     
- Misses      12847    12968     +121     
  Partials      460      460              

Impacted Files	Coverage Δ
fury/actor.py	0.00% <0.00%> (ø)
fury/fury/actor.py	86.68% <0.00%> (-1.88%)	:arrow_down:
fury/ui/elements.py	0.00% <0.00%> (ø)
fury/ui/tests/test_elements.py	0.00% <0.00%> (ø)
fury/fury/ui/elements.py	90.17% <0.00%> (+0.27%)	:arrow_up:
fury/fury/ui/tests/test_elements.py	80.50% <0.00%> (+0.34%)	:arrow_up:
fury/fury/ui/containers.py	83.37% <0.00%> (+0.44%)	:arrow_up:

[m-agour]

Hello @guaje @filipinascimento , I updated this PR and changed the tutorial to display impostor sphere actors on billboards as shown below

https://user-images.githubusercontent.com/63170874/182064895-27fdd00a-6372-4caa-aff6-3a4bad64e407.mp4

I will make an example of animating (scaling and changing the color of spheres) before today's meeting. Also will put it under the pressure of thousands of spheres at once.

[skoudoro]

Can you rebase and fix the conflicts of this PR?

Thank you