Area :: Discussions

Feedback

Tell us what you think of the site.

Send Feedback

AREA
Digital Entertainment
& Visualization Community

Autodesk Media & Entertainment User Community

Latest Blogs

My Oh Maya!
Maya Bonus Tools Resource Page (New Updates)

maxTD
maxTD lives on Vimeo

3D SDK and Scripting Mayhem
The 3ds Max 2013 .NET SDK and MaxSharp Source Code

More Blogs

Software Trials

Autodesk® 3ds Max®

Download Trial

Autodesk® Maya®

Download Trial

Autodesk® Softimage®

Download Trial

Autodesk® MotionBuilder®

Download Trial

Autodesk® Mudbox™

Download Trial

Autodesk® Sketchbook® Pro

Download Trial

Autodesk® Smoke on Mac®

Download Trial

RSS 2.0

ATOM

ComputeFieldOfView - vertical or horizontal?

Rate this thread

Permlink of this thread

Paulius Liekis

Paulius Liekis
Posted: 15 November 2011 01:34 AM

Location: Kaunas
Total Posts: 32
Joined: 11 December 2009 06:23 AM

Hi,

Could you tell me which FOV ComputeFieldOfView returns - vertical or horizontal?

Thanks,
Paulius Liekis
http://unity3d.com
http://pixel-punch.com

Replies: 0

Viviane.Rochon

Viviane.Rochon
Posted: 16 November 2011 08:03 AM

Location: Montréal
Total Posts: 395
Joined: 11 July 2007 08:47 AM
Permlink of this post

Hi Paulius,

This method will compute the FOV according to the actual ApertureMode.

Regards,

Viviane Rochon
Maya Data Platform
Autodesk

Replies: 1

I’m either misusing the method or I don’t understand your answer. What will ComputeFieldOfView return (horizontal or vertical FOV) when ApertureMode is eFOCAL_LENGTH? what if ApertureMode is eHORIZONTAL_AND_VERTICAL?

I have the same question about ComputeFocalLength: which pAngleOfView has to be passed? horizontal or vertical?

Author: Paulius Liekis

Replied: 17 November 2011 08:37 PM

Robert Goulet

Robert Goulet
Posted: 21 November 2011 06:01 AM

Location: Montreal
Total Posts: 84
Joined: 13 March 2009 04:04 PM
Permlink of this post

Hi Paulius,

here’s how the ComputeFieldOfView function is implemented in FBX 2013.0 right now:

double FbxCamera::ComputeFieldOfView(double pFocalLength) const
{

    if( pFocalLength == 0 ) return 0.0;

    double lApertureHeight = FilmHeight.Get() * FBXSDK_IN_TO_MM;

    double lApertureWidth = FilmWidth.Get() * FBXSDK_IN_TO_MM;

    if( ApertureMode.Get() == eVERTICAL )

    {

        return atan((lApertureHeight / pFocalLength) * 0.5) * 2.0 * FBXSDK_180_DIV_PI;

    }

    return atan((lApertureWidth * FilmSqueezeRatio.Get() / pFocalLength) * 0.5 ) * 2.0 * FBXSDK_180_DIV_PI;
}

ComputeFocalLength is very similar:

double FbxCamera::ComputeFocalLength(double pAngleOfView) const
{

    if( pAngleOfView == 0 ) return 0.0;

    double lApertureHeight = FilmHeight.Get() * FBXSDK_IN_TO_MM;

    double lApertureWidth = FilmWidth.Get() * FBXSDK_IN_TO_MM;

    if( ApertureMode.Get() == eVERTICAL )

    {

        return (lApertureHeight / tan(pAngleOfView * FBXSDK_PI_DIV_180 * 0.5)) * 0.5;

    }

    return (lApertureWidth * FilmSqueezeRatio.Get() / tan(pAngleOfView * FBXSDK_PI_DIV_180 * 0.5)) * 0.5;
}

As you can see, we don’t do anything particuliar for the eFOCAL_LENGTH mode, but it seems we handle the vertical case differently from the other modes. Hopefully this help you choose which mode you need to use.

Robert Goulet, FBX Dev Lead

Replies: 1

Ah I see, so ComputeFieldOfView returns vertical FOV when ApertureMode==eVERTICAL and horizontal FOV when aperture mode is eHORIZONTAL, eHORIZONTAL_AND_VERTICAL or eFOCAL_LENGTH.

It would be great to find such info in the documentation ;)

Thanks,
Paulius

Author: Paulius Liekis

Replied: 21 November 2011 10:04 PM

General

Autodesk 3ds Max

Autodesk Softimage

Autodesk Maya

Autodesk Mudbox

Creative Finishing

Product Communities