Missing penultimate frame in GP interpolation sequence #66941

New Issue

James Griffin · 2019-07-14T22:15:46+02:00

James Griffin commented

2019-07-14 22:15:46 +02:00

System Information
Operating system: Windows-10-10.0.17763 64 Bits
Graphics card: GeForce GT 630M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 391.35

Blender Version
Broken: version: 2.80 (sub 74), branch: master, commit date: 2019-07-11 13:50, hash: 06312c6d2d
Worked: (optional)

Short description of error
When using Interpolate->Sequence with the grease pencil, the interpolation factors for each intermediate frame are incorrectly calculated, resulting in the final step being double the other intermediate steps.sequence_error.blend

You can see this in the attached file by moving between frames 8, 9 and 10.

Exact steps for others to reproduce the error
See attached blend file.

Fix
I don't have the dev tools to double check, but the error is in editors/gpencil/gpencil_interpolate.c, line 1000:
https://git.blender.org/gitweb/gitweb.cgi/blender.git/blob/HEAD:/source/blender/editors/gpencil/gpencil_interpolate.c

The + 1 is superfluous, the two lines calculating factor should be:

998       /* get interpolation factor */
 999       factor = (float)(cframe - prevFrame->framenum) /
1000                (nextFrame->framenum - prevFrame->framenum);

Obviously in principle the 'framenum's of the adjacent frames should never be equal, but I don't know the code well enough to comment.

**System Information** Operating system: Windows-10-10.0.17763 64 Bits Graphics card: GeForce GT 630M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 391.35 **Blender Version** Broken: version: 2.80 (sub 74), branch: master, commit date: 2019-07-11 13:50, hash: `06312c6d2d` Worked: (optional) **Short description of error** When using Interpolate->Sequence with the grease pencil, the interpolation factors for each intermediate frame are incorrectly calculated, resulting in the final step being double the other intermediate steps.[sequence_error.blend](https://archive.blender.org/developer/F7608853/sequence_error.blend) You can see this in the attached file by moving between frames 8, 9 and 10. **Exact steps for others to reproduce the error** See attached blend file. **Fix** I don't have the dev tools to double check, but the error is in editors/gpencil/gpencil_interpolate.c, line 1000: [[ https://git.blender.org/gitweb/gitweb.cgi/blender.git/blob/HEAD:/source/blender/editors/gpencil/gpencil_interpolate.c ]] The + 1 is superfluous, the two lines calculating factor should be: ``` 998 /* get interpolation factor */ 999 factor = (float)(cframe - prevFrame->framenum) / 1000 (nextFrame->framenum - prevFrame->framenum); ``` Obviously in principle the 'framenum's of the adjacent frames should never be equal, but I don't know the code well enough to comment.

James Griffin commented

2019-07-14 22:15:46 +02:00

Added subscriber: @MagnumOctopus

Antonio Vazquez self-assigned this 2019-07-15 10:00:26 +02:00

blender-admin commented

2019-07-15 16:56:32 +02:00

This issue was referenced by 69aa5bba4f

This issue was referenced by 69aa5bba4f0ccd9e95ce2eb811e0f7089fbb5574

Antonio Vazquez commented

2019-07-15 16:57:03 +02:00

Changed status from 'Open' to: 'Resolved'

Antonio Vazquez closed this issue

2019-07-15 16:57:03 +02:00

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Missing penultimate frame in GP interpolation sequence #66941