From 6e9fc3e6446e5b261f6e943859f867c54bc6269d Mon Sep 17 00:00:00 2001
From: Dan Bagnell <daniel.p.bagnell@gmail.com>
Date: Mon, 9 Apr 2018 09:13:06 -0400
Subject: [PATCH] Use eye coordinates instead of window coordinates in the
 billboard vertex shader.

---
 Source/Shaders/BillboardCollectionVS.glsl | 26 +++++++++++------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/Source/Shaders/BillboardCollectionVS.glsl b/Source/Shaders/BillboardCollectionVS.glsl
index cf0f97840e3d..039bd3323928 100644
--- a/Source/Shaders/BillboardCollectionVS.glsl
+++ b/Source/Shaders/BillboardCollectionVS.glsl
@@ -71,23 +71,23 @@ vec4 computePositionWindowCoordinates(vec4 positionEC, vec2 imageSize, float sca
         positionEC.xy += halfSize;
     }
 
-    vec4 positionWC = czm_eyeToWindowCoordinates(positionEC);
+    float mpp = czm_metersPerPixel(positionEC);
 
-    if (sizeInMeters)
+    if (!sizeInMeters)
     {
-        originTranslate /= czm_metersPerPixel(positionEC);
+        originTranslate *= mpp;
     }
 
-    positionWC.xy += originTranslate;
+    positionEC.xy += originTranslate;
     if (!sizeInMeters)
     {
-        positionWC.xy += halfSize;
+        positionEC.xy += halfSize * mpp;
     }
 
-    positionWC.xy += translate;
-    positionWC.xy += (pixelOffset * czm_resolutionScale);
+    positionEC.xy += translate * mpp;
+    positionEC.xy += (pixelOffset * czm_resolutionScale) * mpp;
 
-    return positionWC;
+    return positionEC;
 }
 
 void main()
@@ -255,14 +255,14 @@ void main()
     }
 #endif
 
-#ifdef LOG_DEPTH
-    czm_vertexLogDepth(czm_projection * positionEC);
-#endif
-
     vec4 positionWC = computePositionWindowCoordinates(positionEC, imageSize, scale, direction, origin, translate, pixelOffset, alignedAxis, validAlignedAxis, rotation, sizeInMeters);
-    gl_Position = czm_viewportOrthographic * vec4(positionWC.xy, -positionWC.z, 1.0);
+    gl_Position = czm_projection * positionWC;
     v_textureCoordinates = textureCoordinates;
 
+#ifdef LOG_DEPTH
+    czm_vertexLogDepth();
+#endif
+
 #ifdef DISABLE_DEPTH_DISTANCE
     float disableDepthTestDistance = distanceDisplayConditionAndDisableDepth.z;
     if (disableDepthTestDistance == 0.0 && czm_minimumDisableDepthTestDistance != 0.0)