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## zoom

Specify rendering scale.

### Shortcuts:

> Key macro Z implements a zoom-out function.
> Key macro z implements a zoom-in function.
> Key macro < decreases the vertical scale.
> Key macro > increases the vertical scale.

### Usage:

> zoom [xy z]

> > where xy is the scale in both x and y dimensions (which cannot be set differently from each other), and z is the scale in the z (vertical) direction.

### Summary:

> The zoom command changes the scale of the 3D rendering, effectively moving the viewpoint closer to or farther away from the vertical axis origin.

> Three-dimensional rendered views of layout usually exaggerate the vertical axis (like topographical maps of the Earth) to allow the vertical structure to be more readily viewed and understood. The vertical axis scaling is therefore arbritrary, and may be set independently of the other axes.

> Note that the z-axis value is represented such that it is independent of changes in the xy zooming. Key macros implementing zoom-in and zoom-out functions effectively change the scaling factor of all three viewing axes simultaneously, so that the vertical scale remains proportional to the horizontal scales. This does not change the zoom value of z reported by the zoom command.

> Without arguments, zoom returns the current scalefactors in both the xy axes (combined) and z axis.

### Implementation Notes:

> zoom is implemented as a built-in wind3d window command in magic. It overrides the default window client zoom command. Note that the wind3d window is only available when magic is compiled with the OpenGL graphics option and invoked with magic -d OGL.

> Note that macros of the wind3d window are hard-coded, and cannot be changed with the macro, gmacro, or imacro commands. There is no "`:`" macro for entering commands; to enter commands from the command-line, use the tk_path_name command. The default Tk path name of the wind3d window is "`.magic3d`".

### See Also:

> scroll
> view

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Last updated: October, 2004