Bug 217 – kinematics should allow true spherical joint

Khronos Public Bugzilla

Bug 217 - kinematics should allow true spherical joint

Summary:

kinematics should allow true spherical joint

Status:	NEW

Product:	COLLADA
Classification:	Unclassified
Component:	Schema
Version:	1.5.0
Platform:	PC Linux

Importance:	P3 normal
Target Milestone:	---
Assigned To:	Mark Barnes
QA Contact:	COLLADA Work Group email alias

URL:
Keywords:

Depends on:
Blocks:
	Show dependency tree / graph

Reported:	2009-10-08 11:16 PDT by Marty Vona
Modified:	2009-10-08 11:16 PDT (History)
CC List:	0 users

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Description Marty Vona 2009-10-08 11:16:45 PDT

There is a difference between a true spherical joint and a compound joint that has three stacked orthogonal revolute axes: the latter can be gimbal locked but the former cannot.  It appears that only the latter can currently be expressed in the 1.5 joint schema.  It would be useful to also allow true spherical joints.

Even though extra elements are currently permitted as children of the joint element, there does not appear to be a clean way to use this mechanism to specify a spherical joint, because at least one revolute or prismatic element must also be a child of every joint element.