Merge pull request #4990 from AnalyticalGraphicsInc/pick-position

Scene.pickPosition in 2D/CV

Author: pjcozzi

Apps/Sandcastle/gallery/Picking.html

@@ -174,17 +174,16 @@
         }
     });
 
-    var sceneModeWarningPosted = false;
-
     // Mouse over the globe to see the cartographic position
     handler = new Cesium.ScreenSpaceEventHandler(scene.canvas);
     handler.setInputAction(function(movement) {
+
         var foundPosition = false;
 
         var scene = viewer.scene;
-        var pickedObject = scene.pick(movement.endPosition);
-        if (scene.pickPositionSupported && Cesium.defined(pickedObject) && pickedObject.id === modelEntity) {
-            if (scene.mode === Cesium.SceneMode.SCENE3D) {
+        if (scene.mode !== Cesium.SceneMode.MORPHING) {
+            var pickedObject = scene.pick(movement.endPosition);
+            if (scene.pickPositionSupported && Cesium.defined(pickedObject) && pickedObject.id === modelEntity) {
                 var cartesian = viewer.scene.pickPosition(movement.endPosition);
 
                 if (Cesium.defined(cartesian)) {
@@ -200,14 +199,10 @@
                         '\nLat: ' + ('   ' + latitudeString).slice(-7) + '\u00B0' +
                         '\nAlt: ' + ('   ' + heightString).slice(-7) + 'm';
 
-                    var camera = scene.camera;
-                    labelEntity.label.eyeOffset = new Cesium.Cartesian3(0.0, 0.0, camera.frustum.near * 1.5 - Cesium.Cartesian3.distance(cartesian, camera.position));
+                    labelEntity.label.eyeOffset = new Cesium.Cartesian3(0.0, 0.0, -cartographic.height * (scene.mode === Cesium.SceneMode.SCENE2D ? 1.5 : 1.0));
 
                     foundPosition = true;
                 }
-            } else if (!sceneModeWarningPosted) {
-                sceneModeWarningPosted = true;
-                console.log("pickPosition is currently only supported in 3D mode.");
             }
         }
 

CHANGES.md

@@ -23,6 +23,7 @@ Change Log
 * Fixed an issue where the camera would zoom past an object and flip to the other side of the globe. [#4967](https://github.com/AnalyticalGraphicsInc/cesium/pull/4967) and [#4982](https://github.com/AnalyticalGraphicsInc/cesium/pull/4982)
 * Fixed exception in 2D in certain cases with polylines when rotating the map. [#4619](https://github.com/AnalyticalGraphicsInc/cesium/issues/4619)
 * Fixed an issue with constant `VertexArray` attributes not being set correctly. [#4995](https://github.com/AnalyticalGraphicsInc/cesium/pull/4995)
+* Add support for `Scene.pickPosition` in Columbus view and 2D. [#4990](https://github.com/AnalyticalGraphicsInc/cesium/pull/4990)
 
 ### 1.30 - 2017-02-01
 

Source/Scene/Scene.js

@@ -2701,15 +2701,18 @@ define([
 
     /**
      * Returns the cartesian position reconstructed from the depth buffer and window position.
+     * The returned position is in world coordinates. Used internally by camera functions to
+     * prevent conversion to projected 2D coordinates and then back.
+     *
+     * @private
      *
      * @param {Cartesian2} windowPosition Window coordinates to perform picking on.
      * @param {Cartesian3} [result] The object on which to restore the result.
-     * @returns {Cartesian3} The cartesian position.
+     * @returns {Cartesian3} The cartesian position in world coordinates.
      *
      * @exception {DeveloperError} Picking from the depth buffer is not supported. Check pickPositionSupported.
-     * @exception {DeveloperError} 2D is not supported. An orthographic projection matrix is not invertible.
      */
-    Scene.prototype.pickPosition = function(windowPosition, result) {
+    Scene.prototype.pickPositionWorldCoordinates = function(windowPosition, result) {
         if (!this.useDepthPicking) {
             return undefined;
         }
@@ -2738,9 +2741,7 @@ define([
         } else if (defined(camera.frustum.infiniteProjectionMatrix)){
             frustum = camera.frustum.clone(scratchPerspectiveOffCenterFrustum);
         } else {
-            //>>includeStart('debug', pragmas.debug);
-            throw new DeveloperError('2D is not supported. An orthographic projection matrix is not invertible.');
-            //>>includeEnd('debug');
+            frustum = camera.frustum.clone(scratchOrthographicFrustum);
         }
 
         var numFrustums = this.numberOfFrustums;
@@ -2760,17 +2761,64 @@ define([
 
             if (depth > 0.0 && depth < 1.0) {
                 var renderedFrustum = this._frustumCommandsList[i];
-                frustum.near = renderedFrustum.near * (i !== 0 ? OPAQUE_FRUSTUM_NEAR_OFFSET : 1.0);
-                frustum.far = renderedFrustum.far;
-                uniformState.updateFrustum(frustum);
+                var height2D;
+                if (this.mode === SceneMode.SCENE2D) {
+                    height2D = camera.position.z;
+                    camera.position.z = height2D - renderedFrustum.near + 1.0;
+                    frustum.far = Math.max(1.0, renderedFrustum.far - renderedFrustum.near);
+                    frustum.near = 1.0;
+                    uniformState.update(this.frameState);
+                    uniformState.updateFrustum(frustum);
+                } else {
+                    frustum.near = renderedFrustum.near * (i !== 0 ? OPAQUE_FRUSTUM_NEAR_OFFSET : 1.0);
+                    frustum.far = renderedFrustum.far;
+                    uniformState.updateFrustum(frustum);
+                }
+
+                result = SceneTransforms.drawingBufferToWgs84Coordinates(this, drawingBufferPosition, depth, result);
 
-                return SceneTransforms.drawingBufferToWgs84Coordinates(this, drawingBufferPosition, depth, result);
+                if (this.mode === SceneMode.SCENE2D) {
+                    camera.position.z = height2D;
+                    uniformState.update(this.frameState);
+                }
+
+                return result;
             }
         }
 
         return undefined;
     };
 
+    var scratchPickPositionCartographic = new Cartographic();
+
+    /**
+     * Returns the cartesian position reconstructed from the depth buffer and window position.
+     * <p>
+     * The position reconstructed from the depth buffer in 2D may be slightly different from those
+     * reconstructed in 3D and Columbus view. This is caused by the difference in the distribution
+     * of depth values of perspective and orthographic projection.
+     * </p>
+     *
+     * @param {Cartesian2} windowPosition Window coordinates to perform picking on.
+     * @param {Cartesian3} [result] The object on which to restore the result.
+     * @returns {Cartesian3} The cartesian position.
+     *
+     * @exception {DeveloperError} Picking from the depth buffer is not supported. Check pickPositionSupported.
+     */
+    Scene.prototype.pickPosition = function(windowPosition, result) {
+        result = this.pickPositionWorldCoordinates(windowPosition, result);
+        if (defined(result) && this.mode !== SceneMode.SCENE3D) {
+            Cartesian3.fromElements(result.y, result.z, result.x, result);
+
+            var projection = this.mapProjection;
+            var ellipsoid = projection.ellipsoid;
+
+            var cart = projection.unproject(result, scratchPickPositionCartographic);
+            ellipsoid.cartographicToCartesian(cart, result);
+        }
+        return result;
+    };
+
     /**
      * Returns a list of objects, each containing a `primitive` property, for all primitives at
      * a particular window coordinate position. Other properties may also be set depending on the

Source/Scene/SceneTransforms.js

@@ -320,11 +320,24 @@ define([
         ndc.z = (depth * 2.0) - 1.0;
         ndc.w = 1.0;
 
-        var worldCoords = Matrix4.multiplyByVector(uniformState.inverseViewProjection, ndc, scratchWorldCoords);
-
-        // Reverse perspective divide
-        var w = 1.0 / worldCoords.w;
-        Cartesian3.multiplyByScalar(worldCoords, w, worldCoords);
+        var worldCoords;
+        var frustum = scene.camera.frustum;
+        if (!defined(frustum.fovy)) {
+            var currentFrustum = uniformState.currentFrustum;
+            worldCoords = scratchWorldCoords;
+            worldCoords.x = (ndc.x * (frustum.right - frustum.left) + frustum.left + frustum.right) * 0.5;
+            worldCoords.y = (ndc.y * (frustum.top - frustum.bottom) + frustum.bottom + frustum.top) * 0.5;
+            worldCoords.z = (ndc.z * (currentFrustum.x - currentFrustum.y) - currentFrustum.x - currentFrustum.y) * 0.5;
+            worldCoords.w = 1.0;
+
+            worldCoords = Matrix4.multiplyByVector(uniformState.inverseView, worldCoords, worldCoords);
+        } else {
+            worldCoords = Matrix4.multiplyByVector(uniformState.inverseViewProjection, ndc, scratchWorldCoords);
+
+            // Reverse perspective divide
+            var w = 1.0 / worldCoords.w;
+            Cartesian3.multiplyByScalar(worldCoords, w, worldCoords);
+        }
 
         return Cartesian3.fromCartesian4(worldCoords, result);
     };

Source/Scene/ScreenSpaceCameraController.js

@@ -806,7 +806,7 @@ define([
 
         var depthIntersection;
         if (scene.pickPositionSupported) {
-            depthIntersection = scene.pickPosition(mousePosition, scratchDepthIntersection);
+            depthIntersection = scene.pickPositionWorldCoordinates(mousePosition, scratchDepthIntersection);
         }
 
         var ray = camera.getPickRay(mousePosition, pickGlobeScratchRay);

Specs/Scene/SceneSpec.js

@@ -8,6 +8,7 @@ defineSuite([
         'Core/Ellipsoid',
         'Core/GeographicProjection',
         'Core/GeometryInstance',
+        'Core/Math',
         'Core/PixelFormat',
         'Core/Rectangle',
         'Core/RectangleGeometry',
@@ -43,6 +44,7 @@ defineSuite([
         Ellipsoid,
         GeographicProjection,
         GeometryInstance,
+        CesiumMath,
         PixelFormat,
         Rectangle,
         RectangleGeometry,
@@ -82,7 +84,7 @@ defineSuite([
         scene.debugCommandFilter = undefined;
         scene.fxaa = false;
         scene.primitives.removeAll();
-        scene.morphTo3D();
+        scene.morphTo3D(0.0);
     });
 
     afterAll(function() {
@@ -628,6 +630,9 @@ defineSuite([
         scene.destroyForSpecs();
     });
 
+    var pickedPosition3D = new Cartesian3(-455845.46867895435, -5210337.548977215, 3637549.8562320103);
+    var pickedPosition2D = new Cartesian3(-455861.7055871038, -5210523.137686572, 3637866.6638769475);
+
     it('pickPosition', function() {
         if (!scene.pickPositionSupported) {
             return;
@@ -652,7 +657,67 @@ defineSuite([
 
         expect(scene).toRenderAndCall(function() {
             var position = scene.pickPosition(windowPosition);
-            expect(position).toBeDefined();
+            expect(position).toEqualEpsilon(pickedPosition3D, CesiumMath.EPSILON6);
+        });
+    });
+
+    it('pickPosition in CV', function() {
+        if (!scene.pickPositionSupported) {
+            return;
+        }
+
+        scene.morphToColumbusView(0.0);
+
+        var rectangle = Rectangle.fromDegrees(-100.0, 30.0, -90.0, 40.0);
+        scene.camera.setView({ destination : rectangle });
+
+        var canvas = scene.canvas;
+        var windowPosition = new Cartesian2(canvas.clientWidth / 2, canvas.clientHeight / 2);
+
+        expect(scene).toRenderAndCall(function() {
+            var position = scene.pickPosition(windowPosition);
+            expect(position).not.toBeDefined();
+
+            var rectanglePrimitive = createRectangle(rectangle);
+            rectanglePrimitive.appearance.material.uniforms.color = new Color(1.0, 0.0, 0.0, 1.0);
+
+            var primitives = scene.primitives;
+            primitives.add(rectanglePrimitive);
+        });
+
+        expect(scene).toRenderAndCall(function() {
+            var position = scene.pickPosition(windowPosition);
+            expect(position).toEqualEpsilon(pickedPosition2D, CesiumMath.EPSILON6);
+        });
+    });
+
+    it('pickPosition in 2D', function() {
+        if (!scene.pickPositionSupported) {
+            return;
+        }
+
+        scene.morphTo2D(0.0);
+
+        var rectangle = Rectangle.fromDegrees(-100.0, 30.0, -90.0, 40.0);
+        scene.camera.setView({ destination : rectangle });
+
+        var canvas = scene.canvas;
+        var windowPosition = new Cartesian2(canvas.clientWidth / 2, canvas.clientHeight / 2);
+
+        expect(scene).toRenderAndCall(function() {
+            var position = scene.pickPosition(windowPosition);
+            expect(position).not.toBeDefined();
+
+            var rectanglePrimitive = createRectangle(rectangle);
+            rectanglePrimitive.appearance.material.uniforms.color = new Color(1.0, 0.0, 0.0, 1.0);
+
+            var primitives = scene.primitives;
+            primitives.add(rectanglePrimitive);
+        });
+
+        expect(scene).toRenderAndCall(function() {
+            var position = scene.pickPosition(windowPosition);
+            expect(position).toEqualEpsilon(pickedPosition2D, CesiumMath.EPSILON6);
         });
     });