[Deimel]

It would probably be nice to also fix it in the current “stable” v15-09 branch.

Best,
Raphael

[Deimel]

Hello Maxime,

Please have a look at the testcase I posted, it doesn’t contain a RigidRigidMapping directive but nevertheless rotates the DOFs around the wrong axis (the DoF’s frame instead of the global frame).

Best,
Raphael

[Deimel]

The forum does not seem to handle code correctly :/

Patch:
http://pastebin.com/cE3X4YEN

Testcase:
http://pastebin.com/X10WnYPH

[Deimel]

Seems like the rotations are applied to MechanicalObject’s in the wrong order. As long as either of the rotation property or the DoF’s orientation in the position property are not set (or set to 0 0 0 1), this bug does not affect the outcome.

Here’s the simple fix:

diff --git a/modules/SofaBaseMechanics/MechanicalObject.cpp b/modules/SofaBaseMechanics/MechanicalObject.cpp
index 074ea8e..9c32cfe 100644
--- a/modules/SofaBaseMechanics/MechanicalObject.cpp
+++ b/modules/SofaBaseMechanics/MechanicalObject.cpp
@@ -132,7 +132,7 @@ void MechanicalObject<defaulttype::Rigid3dTypes>::applyRotation (const defaultty
     for (unsigned int i = 0; i < x.size(); i++)
     {
         x[i].getCenter() = q.rotate(x[i].getCenter());
-        x[i].getOrientation() *= q;
+        x[i].getOrientation() = q * x[i].getOrientation();
     }
 }

It would be nice if somebody with repository access could fix the patch 🙂 Here’s a simple testcase to check the result:

<?xml version="1.0"?>

<!-- the point frame coordinates are rotated in global frame, but the orientation is rotated in local frame -->

<Node 	 name="root"  gravity="0 -9.81 0"  dt="1e-4"  time="0"  >
    <BackgroundSetting name="prettify" color=" 0 0 0" />
  	<ViewerSetting cameraMode="Orthographic" />
	<VisualStyle name="visualStyle1"  displayFlags="showVisual showBehaviorModels hideForceFields showInteractionForceFields hideCollision hideMapping hideOptions" />
	<MultiStepAnimationLoop collisionSteps="1" integrationSteps="5"/>
	
      <MechanicalObject template="Rigid3d" name="DOFs"  
            showObjectScale="2.5"  
            showObject="1" 
            rest_position="
0 0 0       0 0 0 1
32.1804178343 0.0 11.73187801      0.0 0.371991451914 0.0 -0.928236155137
42.4985667543 0.0 38.9022536239      0.0 0.702721776175 0.0 -0.711464760399
		    "
    		translation="0 0 0" 
    		rotation="0 0 0"
		/>
	
      <MechanicalObject template="Rigid3d" name="DOFs"  
            showObjectScale="2.5"  
            showObject="1" 
            rest_position="
0 0 0       0 0 0 1
32.1804178343 0.0 11.73187801      0.0 0.371991451914 0.0 -0.928236155137
42.4985667543 0.0 38.9022536239      0.0 0.702721776175 0.0 -0.711464760399
		    "
    		translation="0 0 0" 
    		rotation="0 0 30"
		/>
 
	</Node>
</Node>

[Deimel]

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