Merge pull request #5066 from AnalyticalGraphicsInc/blending-badness

Change blending options in attempt to fix overlapping billboard fringes.
CesiumGS · Mar 16, 2017 · b58120d · b58120d
2 parents ed034db + 514857d
commit b58120d
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Showing 2 changed files with 10 additions and 3 deletions.
diff --git a/CHANGES.md b/CHANGES.md
@@ -11,6 +11,7 @@ Change Log
     * `pitchAdjustHeight` to adjust camera pitch during exaggerated flights, to keep Earth in viewport.
 * Added the event `Viewer.trackedEntityChanged`, which is raised when the value of `viewer.trackedEntity` changes. [#5060](https://github.com/AnalyticalGraphicsInc/cesium/pull/5060)
 * Added `Camera.DEFAULT_OFFSET` for default view of objects with bounding spheres [#4936](https://github.com/AnalyticalGraphicsInc/cesium/pull/4936)
+* Changed billboard blending behavior [#5066](https://github.com/AnalyticalGraphicsInc/cesium/pull/5056)
 * Fix crunch compressed textures in IE11. [#5057](https://github.com/AnalyticalGraphicsInc/cesium/pull/5057)
 * Fixed a bug in `Quaternion.fromHeadingPitchRoll` that made it erroneously throw an exception when passed individual angles in an unminified / debug build.
 * Fix `GroundPrimitive` rendering in 2D and Columbus View [#5078](https://github.com/AnalyticalGraphicsInc/cesium/pull/5078)

diff --git a/Source/Scene/BillboardCollection.js b/Source/Scene/BillboardCollection.js
@@ -1453,21 +1453,27 @@ define([
                 this._rsOpaque = RenderState.fromCache({
                     depthTest : {
                         enabled : true,
-                        func : WebGLConstants.LEQUAL  // Allows label glyphs and billboards to overlap.
+                        func : WebGLConstants.LESS
                     },
                     depthMask : true
                 });
             } else {
                 this._rsOpaque = undefined;
             }
 
+            // If OPAQUE_AND_TRANSLUCENT is in use, only the opaque pass gets the benefit of the depth buffer,
+            // not the translucent pass.  Otherwise, if the TRANSLUCENT pass is on its own, it turns on
+            // a depthMask in lieu of full depth sorting (because it has opaque-ish fragments that look bad in OIT).
+            // When the TRANSLUCENT depth mask is in use, label backgrounds require the depth func to be LEQUAL.
+            var useTranslucentDepthMask = this._blendOption === BlendOption.TRANSLUCENT;
+
             if (this._blendOption === BlendOption.TRANSLUCENT || this._blendOption === BlendOption.OPAQUE_AND_TRANSLUCENT) {
                 this._rsTranslucent = RenderState.fromCache({
                     depthTest : {
                         enabled : true,
-                        func : WebGLConstants.LEQUAL  // Allows label glyphs and billboards to overlap.
+                        func : (useTranslucentDepthMask ? WebGLConstants.LEQUAL : WebGLConstants.LESS)
                     },
-                    depthMask : this._blendOption === BlendOption.TRANSLUCENT,
+                    depthMask : useTranslucentDepthMask,
                     blending : BlendingState.ALPHA_BLEND
                 });
             } else {