id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	blockedby	blocking	notify_on_close	platform	project
1818	Normals incorrect for instanced objects different scaling along each axis	Tristan Croll	Tom Goddard	"Context is a new ""adaptive"" distance restraint scheme (see https://twitter.com/CrollTristan/status/1113122594616741890). To represent the restraints, I'm using a cylinder (`surface.shapes.cylinder_geometry()`) for the target distance, connected at each end to the restrained atoms with cones (`surface.shapes.cone_geometry()`). Zooming in on a set of stretched restraints, the cone normals are all wrong (see attached picture). Looks to me like they're being transformed in the same way as the vertices themselves, which is only correct when the transformation is strictly rotation/scale or when there is no skew component parallel to the normal. From what I gather, the generally correct transformation for normals is the transpose of the inverse of the vertex transform. I can see it would be a horrible waste of resources to use that everywhere, but would it be possible to provide an optional switch on `Drawing` to turn on the strict treatment?"	defect	closed	minor		Graphics		wontfix						all	ChimeraX