Re: [K3d-development] Viewport spinning

[Timothy M. S. <ts...@k-...>]

Russell Senior wrote:

> One other niggling little detail I've noticed.  I've been flipping the
> coordinate system so that Z is "vertical" (I know that isn't the
> standard computer graphics way, but with the group of people I'm
> working with it communicates better).  However, I can't seem to spin
> the CameraViewport around "the way I want"[1] with the Right Mouse
> Button.  I thought maybe the X,Y,Z drop-down menu (rightmost on the
> top line of buttons on the Viewport) might alter that, but it doesn't
> seem to.  What is the X,Y,Z drop-down supposed to do.  This is with
> 4.3.0, but I think I saw the same thing with 4.2.0.

The Active Axis controls affect how 2D mouse coordinates are mapped to 
3D for many of the tools.  It doesn't have any impact on viewport 
navigation.

The "orbiting" behavior in the viewport is designed to be good for 
modeling, but it does introduce gimbal-lock and is hard-coded with the 
assumption that +Y == "up".

Why not model your stick figures with +Y == "up", then add a rotation to 
your export plugin to adjust the output to what your collaborators 
expect?  Change

   k3d::world_position(*Object)

to

   k3d::rotation3D(k3d::radians(-90), k3d::vector3(1, 0, 0)) *
     k3d::world_position(*Object)

in your code (I might have the sign wrong, but you get the point).  You 
might also want to adjust the orientation of the Axes object in your 
document to match as an aid to visualization.

Cheers,
Tim