# Frustrum is NaN

**URL:** <https://community.cesium.com/t/frustrum-is-nan/1751>\
**Category:** CesiumJS\
**Created:** [December 11, 2014, 8:51am UTC](https://community.cesium.com/t/frustrum-is-nan/1751 "2014-12-11T08:51:03Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![xavier\_lhomme](https://avatars.discourse-cdn.com/v4/letter/x/e5b9ba/32.png) [@xavier\_lhomme](https://community.cesium.com/u/xavier_lhomme)\
**Post date:** [December 11, 2014, 8:51am UTC](https://community.cesium.com/t/frustrum-is-nan/1751/1 "2014-12-11T08:51:03Z")

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Hi

(Cesium 1.3)

sometimes , I’ve got a Nan value for “far”. And thenthe folloxing function return a numFrustums as NaN.

and updateFrustums failed due to the line frustumCommandsList.length.

var numFrustums = Math.ceil(Math.log(far / near) / Math.log(farToNearRatio));

if (near !== Number.MAX\_VALUE && (numFrustums !== numberOfFrustums || (frustumCommandsList.length !== 0 &&

(near \< frustumCommandsList[0].near || far \> frustumCommandsList[numberOfFrustums - 1].far)))) {

updateFrustums(near, far, farToNearRatio, numFrustums, frustumCommandsList);

createPotentiallyVisibleSet(scene);

Best Regards

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<div class="post-metadata">

**Author:** ![patrick](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/patrick/32/2045_2.png) [@patrick](https://community.cesium.com/u/patrick)\
**Post date:** [December 12, 2014, 1:35am UTC](https://community.cesium.com/t/frustrum-is-nan/1751/2 "2014-12-12T01:35:38Z")

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Can you consistently reproduce it like [https://github.com/AnalyticalGraphicsInc/cesium/issues/2317](https://github.com/AnalyticalGraphicsInc/cesium/issues/2317)

Patrick

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<div class="post-metadata">

**Author:** ![xavier\_lhomme](https://avatars.discourse-cdn.com/v4/letter/x/e5b9ba/32.png) [@xavier\_lhomme](https://community.cesium.com/u/xavier_lhomme)\
**Post date:** [December 12, 2014, 7:56am UTC](https://community.cesium.com/t/frustrum-is-nan/1751/3 "2014-12-12T07:56:17Z")

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No, I had this issue with my terrain provider , when I forget todefine the levelZeroMaximumGeometricError.  
Once I added the Cesium.TerrainProvider.getEstimatedLevelZeroGeometricErrorForAHeightmap in order to define my variable.I don’t have this problem anymore.

But perhaps you should detect such issue in the code (NaN .) and reset properly the camera…