Re: Understanding x, y, z, zoom, and focus interaction.

Gregory Sogorka wrote:

I am trying to wrap my head around the relevance and interaction of
these values.  So it seems to me there are a number of values
affecting a Camera3D object which when insulated I think I understand.
 But when these values begin to interact with dimension passed to
constructors such as cubes my understanding becomes a bit hazy.



Let me be a bit more descriptive:

1. I have a cube that I am creating with constant dimensions 100x100x100

:::: new Cube ( _ml, 100, 100, 100 )

2. I have read through the classes for the Camera3D object and think I
understand the differences between zoom and focus. As the class
states, the zoom is the scale at which the 3D objects are rendered;
and the focus is the closest a camera can be to any object.


Now I have run some tests and rendered the cube and measured it
dimensions with a pixel ruler tool from Art Directors Toolkit.

constants throughout my experiment were:

camera3d.x = 0;
camera3d.y = 0;
camera3d.zoom = 2; ( as set by the constructor )
camera3d.focus = 100; ( as set by the constructor );






with those constant values I altered the z value of the camera3d
object and measured the width of the resulting cube:

z = 50 width = 200;
z = 75 width = 165;
z= 100 width = 142;
z = 125 width = 125;
z = 150 width = 112;
z = 175 width = 100;


So my question is  why does the z of 175 result in the actual pixel
width sent to the cube constructor being rendered on teh screen.  I am
looking for some sort of pattern in the changes but  cant seem to
grasp it. Could anyone help me out with some illumination to this
simple concept and the broader picture of how all these values
interact with one another ? or point me to a tutorial that maps these
things out clearly.


All the best.
G

_______________________________________________
Papervision3D mailing list
Papervision3D@osflash.org
http://osflash.org/mailman/listinfo/papervision3d_osflash.org