Blender Foundation: Blender 2.x BF release: Detail: 25732 Incorrect shear matrix in XY plane

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[#25732] Incorrect shear matrix in XY plane

Date:
2011-01-20 09:10 Priority:
3

State:
Closed

Submitted by:
Lawrence D'Oliveiro (ldo) Assigned to:
Campbell Barton (campbellbarton)

Category:
Python Status:
Fixed / Closed

Relates to: Duplicates:

Patches:

Summary:
Incorrect shear matrix in XY plane

Detailed description

mathutils.Matrix.Shear incorrectly sets the Z→Z matrix element to 0 when compuing a shear in the XY plane. For example, the three expressions

mathutils.Matrix.Shear("XZ", 0, 4)
mathutils.Matrix.Shear("YZ", 0, 4)
mathutils.Matrix.Shear("XY", 0, 4)

should all return the identity matrix. In fact the last one returns

Matrix((1.0, 0.0, 0.0, 0.0),
(0.0, 1.0, 0.0, 0.0),
(0.0, 0.0, 0.0, 0.0),
(0.0, 0.0, 0.0, 1.0))

Notice the third row is all zeroes, when it should be

(0.0, 0.0, 1.0, 0.0),

Followup

Message

Date: 2011-01-20 23:39
Sender: Lawrence D'Oliveiro
Attached fix.

Date: 2011-01-21 03:37
Sender: Campbell Barton
applied fix however I dont think this function works correctly still.
looking further.

Date: 2011-01-21 04:27
Sender: Campbell Barton
added ability to set the value of the shear axis: http://markmail.org/message/iuxlrz3douwrxdxu

Attached Files:

Name	Date	Download

blender-shear-bug.patch	2011-01-20 23:39	Download

Changes:

Field	Old Value	Date	By

Status	Investigate	2011-01-21 03:37	campbellbarton
status_id	Open	2011-01-21 03:37	campbellbarton
close_date	None	2011-01-21 03:37	campbellbarton
File Added	14661: blender-shear-bug.patch	2011-01-20 23:39	ldo
assigned_to	none	2011-01-20 12:06	ton
Status	New	2011-01-20 12:06	ton