Blender Git Loki
Git Commits -> Revision 9075ec8
Revision 9075ec8 by Bogdan Nagirniak (master) March 13, 2020, 11:59 (GMT) |
Python: add foreach_get and foreach_set methods to pyrna_prop_array This allows fast access to various arrays in the Python API. Most notably, `image.pixels` can be accessed much more efficiently now. **Benchmark** Below are the results of a benchmark that compares different ways to set/get all pixel values. I do the tests on 2048x2048 rgba images. The benchmark tests the following dimensions: - Byte vs. float per color channel - Python list vs. numpy array containing floats - `foreach_set` (new) vs. `image.pixels = ...` (old) ``` Pixel amount: 2048 * 2048 = 4.194.304 Byte buffer size: 16.8 mb Float buffer size: 67.1 mb Set pixel colors: byte - new - list: 271 ms byte - new - buffer: 29 ms byte - old - list: 350 ms byte - old - buffer: 2900 ms float - new - list: 249 ms float - new - buffer: 8 ms float - old - list: 330 ms float - old - buffer: 2880 ms Get pixel colors: byte - list: 128 ms byte - buffer: 9 ms float - list: 125 ms float - buffer: 8 ms ``` **Observations** The best set and get speed can be achieved with buffers and a float image, at the cost of higher memory consumption. Furthermore, using buffers when using `pixels = ...` is incredibly slow, because it is not optimized. Optimizing this is possible, but might not be trivial (there were multiple attempts afaik). Float images are faster due to overhead introduced by the api for byte images. If I profiled it correctly, a lot of time is spend in the `[0, 1] -> {0, ..., 255}` conversion. The functions doing that conversion is `unit_float_to_uchar_clamp`. While I have an idea on how it can be optimized, I do not know if it can be done without changing its functionality slightly. Performance wise the best solution would be to not do this conversion at all and accept byte input from the api user directly, but that seems to be a more involved task as well. Differential Revision: https://developer.blender.org/D7053 Reviewers: JacquesLucke, mont29 |
Commit Details:
Full Hash: 9075ec8269e7cb029f4fab6c1289eb2f1ae2858a
Parent Commit: db4298c
Committed By: Jacques Lucke
Lines Changed: +267, -0
1 Added Path:
/tests/python/bl_pyapi_prop_array.py (+85, -0) (View)