Merge pull request #8109 from AnalyticalGraphicsInc/gee-heights

Fix GEE terrain negative altitude handling
CesiumGS · Sep 3, 2019 · 002d4f0 · 002d4f0
2 parents e0e010a + b317784
commit 002d4f0
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Showing 2 changed files with 10 additions and 7 deletions.
diff --git a/CHANGES.md b/CHANGES.md
@@ -5,7 +5,7 @@ Change Log
 
 ##### Additions :tada:
 * Added optional `index` parameter to `PrimitiveCollection.add`. [#8041](https://github.com/AnalyticalGraphicsInc/cesium/pull/8041)
-* Cesium now renders at native device resolution by default instead of CSS pixel resolution, to go back to the old behavior, `viewer.resolutionScale = 1.0 / window.devicePixelRatio`. [#8082](https://github.com/AnalyticalGraphicsInc/cesium/issues/8082)  
+* Cesium now renders at native device resolution by default instead of CSS pixel resolution, to go back to the old behavior, `viewer.resolutionScale = 1.0 / window.devicePixelRatio`. [#8082](https://github.com/AnalyticalGraphicsInc/cesium/issues/8082)
 * Added `getByName` method to `DataSourceCollection` allowing to retreive `DataSource`s by their name property from the collection
 
 ##### Fixes :wrench:
@@ -14,7 +14,8 @@ Change Log
 * Fixed post-processing selection filtering to work for bloom. [#7984](https://github.com/AnalyticalGraphicsInc/cesium/issues/7984)
 * Disabled HDR by default to improve visual quality in most standard use cases. Set `viewer.scene.highDynamicRange = true` to re-enable. [#7966](https://github.com/AnalyticalGraphicsInc/cesium/issues/7966)
 * Fixed a bug that causes hidden point primitives to still appear on some operating systems. [#8043](https://github.com/AnalyticalGraphicsInc/cesium/issues/8043)
-* Fixed issue where KTX or CRN files would not be properly identified. [#7979](https://github.com/AnalyticalGraphicsInc/cesium/issues/7979) 
+* Fix negative altitude altitide handling in `GoogleEarthEnterpriseTerrainProvider`. [#8109](https://github.com/AnalyticalGraphicsInc/cesium/pull/8109)
+* Fixed issue where KTX or CRN files would not be properly identified. [#7979](https://github.com/AnalyticalGraphicsInc/cesium/issues/7979)
 * Fixed multiple globe materials making the globe darker. [#7726](https://github.com/AnalyticalGraphicsInc/cesium/issues/7726)
 
 ### 1.60 - 2019-08-01

diff --git a/Source/Workers/createVerticesFromGoogleEarthEnterpriseBuffer.js b/Source/Workers/createVerticesFromGoogleEarthEnterpriseBuffer.js
@@ -237,17 +237,19 @@ define([
                 scratchCartographic.longitude = longitude;
                 var latitude = originY + dv.getUint8(offset++) * stepY;
                 scratchCartographic.latitude = latitude;
-                // Height is stored in units of (1/EarthRadius) or (1/6371010.0)
-                var height = dv.getFloat32(offset, true) * 6371010.0;
+
+                var height = dv.getFloat32(offset, true);
                 offset += sizeOfFloat;
 
                 // In order to support old clients, negative altitude values are stored as
                 // height/-2^32. Old clients see the value as really close to 0 but new clients multiply
                 // by -2^32 to get the real negative altitude value.
-                if (height < negativeElevationThreshold) {
-                    height *= negativeAltitudeExponentBias;
+                if (height !== 0 && height < negativeElevationThreshold) {
+                    height *= -Math.pow(2, negativeAltitudeExponentBias);
                 }
-                height *= exaggeration;
+
+                // Height is stored in units of (1/EarthRadius) or (1/6371010.0)
+                height *= 6371010.0 * exaggeration;
 
                 scratchCartographic.height = height;