ID 374504 - Incorrect motion blur in rendered images due to erroneously inserted sample time at 0.0 when resolving constraints

Problem summary:

The ConstraintResolve Op incorrectly calculates sample times, leading to the wrong number of sample times being used when resolving constraints, leading to incorrect motion blur in rendered images. Instead of the correct number of sample times, say 2, an extra sample time at 0.0 is inserted.

Steps to reproduce:

1. Open the attached project.
2. Start a Preview Render from the Render node.

Expected behaviour:

For all rendered frames other than frame 1, the motion blurred white and red spheres align.

Actual behaviour:

For even frames, the motion blurred white and red spheres mostly align, but the red sphere is rendered at an additional position in the top center of the frame. This can be observed most clearly in frame 2.

Workaround:

No known workaround.

Tested versions/platforms:

• 2.5v1 - Affected
• 2.6v1 - Affected
• 3.0v1 - Affected
• 3.1v1 - Affected

Customer version/platform:

3.0v1/Linux