Rotation
 

Hello Vizard Experts,

I am a beginner and need some help. Does anybody know a way (or the code) to allow the user's view to remain stationary (or at least the appearance of it) and to make a constellation of points in space rotate at the same time? We want to create an experiment where students watch a constellation of points while it is rotating so they can understand how all the points relate to each other on a 3-D level but we don't want them to move from their position. Is this possible?

Thanks in advance for your help!

Buster

Hi Buster,

If you attach an object to the HEAD then it will always be centered around the viewer. Let's say that your constellations are in a file called 'constellation.wrl', then you would simply do the following:

stars = viz.add('constellation.wrl',viz.HEAD)

Then when you rotate the model it will be rotating around the head, no matter where the viewer moves.

Are you importing the constellations from a model or generating them on-the-fly? If you're generating them on-the-fly then you would simply do something like the following:

viz.startlayer(viz.POINTS)
viz.vertex(...)
.
.
stars = viz.endlayer(viz.HEAD)

Look at the file spindots.py in the Vizard20/tutorial/onthefly. It is a simple example of creating a sphere of points and rotating them. Good luck!