Greetings,


I've been having some trouble converting from spherical to Cartesian coordinates. The program I am working on is a simulation of stars orbitting the center of a galaxy. Now, I'd like the center of the screen to represent the center of the galaxy and for the stars to orbit around that. However, I've had to do weird things to make my orbits look good and I think it's because I don't fully comprehend how 3D space is represented in Processing.

Normally, to get to Cartesian, I'd do something like:

1. x = cos(theta)*sin(phi)*r;
2. y = sin(theta)*sin(phi)*r;
3. z = cos(phi)*r;

But I want to make it relative to the center of the screen and since the axis are positioned different with positive x right, positive y down, and negative z into the screen, I'm confused exactly how to do it.

What sort of offset do I want? How do I make sure that it orbits something in the center of the screen? Are my equations correct?

Any thoughts would be great.

Greetings,

I want to draw an object (in this case, an orbital path) to a P3D buffer. However, when I try to display it, I'm running into trouble. If I use the image() method, it only displays the buffer in 2d. Any ideas how to overlay my P3D buffer onto my main one?

Cheers,

Justin

When I switch to using P3D, a gray bar about 20 pixels in height spans the top of my window. It offsets everything and it's really weird. mouseX and mouseY still register correctly the positions but when I draw, it offsets it automatically by 20 pixels down. It's really weird and I don't know how to fix it.

Any ideas?

Edit:

So I'm still unsure why Eclipse is giving me this issue but I have a deadline for what I'm working on. When I transfer all of my code to the Processing app, everything works fine.