Camera FOV, Focal Length and Aspect Ratio

[anonymous_user_24cff47d]

We are trying to use Unreal Engine for computer vision experiments and for this we need to know focal length of the camera. The questions we have are,

1. How do you computer focal length from field of view in Unreal Engine?
2. Is FOV in Unreal Engine horizontal or vertical?
3. Is this computation different for Camera component vs SceneCapture2D component?
4. Note that SceneCapture2D doesn’t have aspect ratio. Does this mean we can set any aspect ratio we like?

[Deathrey (DeathreyCG)]

1. There is no relation between focal length and FOV.

2. FOV is horizontal.

3. Same

4. aspect ratio of SceneCapture2D is defined by the resolution of render target, to which the capture is being rendered

[saihv]

Focal length and FOV are related through:

HFOV = 2 * arctan( width / 2f )

[BBB]