Field of View: Difference between revisions

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The field of view (FOV) is the maximum angle between the two sides of a person's or camera's vision. In HL2 and most other games, field of view is a measure of the vertical angle, as resolutions with different aspect ratios must adhere to this vertical field of view, while allowing a different horizontal field of view. This is how widescreen becomes a wider view, rather than just cropping off the top and bottom of the square image.
The [[Field of View]] ('''FOV''') is the maximum angle between the peripherals of a person's or camera's vision. In [[HL2]] and most other games, [[Field of View]] is a measure of the vertical angle, as resolutions with different aspect ratios must adhere to this vertical field of view, while allowing a different horizontal [[Field of View]]. This is how widescreen becomes a wider view, rather than just cropping off the top and bottom of the square image.


The field of view can also be altered to acheive a warping effect, where far objects appear further away and close objects appear closer for example. To obtain the most realistic perspective, the field of view is calculated as the amount of angular space a computer monitor or television takes up in the average user's eyesight.
The [[Field of View]] can also be altered to acheive a warping effect, where far objects appear further away and close objects appear closer for example. To obtain the most realistic perspective, the field of view is calculated as the amount of angular space a computer monitor or television takes up in the average user's eyesight.


Taking the FOV angle into consideration for a standard perspective transform (linear) involves multiplying the Z co-ordinate by the tangent of the field of view divided by 2.
Taking the '''FOV''' angle into consideration for a standard perspective transform (linear) involves multiplying the Z co-ordinate by the tangent of the field of view divided by 2.


: ''z' = z * tan( fov * 0.5 )''
: ''z' = z * tan( fov * 0.5 )''


The most common use of altering the field of view is to simulate zooming, since zooming with a real camera uses the same effect of compressing (or expanding, for wide angle lenses) the depth (z) range.
The most common use of altering the [[Field of View]] is to simulate zooming, since zooming with a real camera uses the same effect of compressing (or expanding, for wide angle lenses) the depth (z) range.


==See Also==
==See Also==

Revision as of 06:21, 20 October 2005

The Field of View (FOV) is the maximum angle between the peripherals of a person's or camera's vision. In HL2 and most other games, Field of View is a measure of the vertical angle, as resolutions with different aspect ratios must adhere to this vertical field of view, while allowing a different horizontal Field of View. This is how widescreen becomes a wider view, rather than just cropping off the top and bottom of the square image.

The Field of View can also be altered to acheive a warping effect, where far objects appear further away and close objects appear closer for example. To obtain the most realistic perspective, the field of view is calculated as the amount of angular space a computer monitor or television takes up in the average user's eyesight.

Taking the FOV angle into consideration for a standard perspective transform (linear) involves multiplying the Z co-ordinate by the tangent of the field of view divided by 2.

z' = z * tan( fov * 0.5 )

The most common use of altering the Field of View is to simulate zooming, since zooming with a real camera uses the same effect of compressing (or expanding, for wide angle lenses) the depth (z) range.

See Also