Merge pull request #970 from jbousquie/feature.Ground.UpdateCoordinateHeights

Feature.ground.update coordinate heights

src/Math/babylon.math.ts

@@ -3705,8 +3705,8 @@
     export class Tmp {
         public static Color3: Color3[] = [Color3.Black(), Color3.Black(), Color3.Black()];
         public static Vector2: Vector2[] = [Vector2.Zero(), Vector2.Zero(), Vector2.Zero()];  // 3 temp Vector2 at once should be enough
-        public static Vector3: Vector3[] = [Vector3.Zero(), Vector3.Zero(), Vector3.Zero()
-            , Vector3.Zero(), Vector3.Zero(), Vector3.Zero()];    // 6 temp Vector3 at once should be enough
+        public static Vector3: Vector3[] = [Vector3.Zero(), Vector3.Zero(), Vector3.Zero(),
+            Vector3.Zero(), Vector3.Zero(), Vector3.Zero(), Vector3.Zero(), Vector3.Zero(), Vector3.Zero()];    // 9 temp Vector3 at once should be enough
         public static Vector4: Vector4[] = [Vector4.Zero(), Vector4.Zero(), Vector4.Zero()];  // 3 temp Vector4 at once should be enough
         public static Quaternion: Quaternion[] = [new Quaternion(0, 0, 0, 0)];                // 1 temp Quaternion at once should be enough
         public static Matrix: Matrix[] = [Matrix.Zero(), Matrix.Zero(),
@@ -3715,5 +3715,3 @@
             Matrix.Zero(), Matrix.Zero()];                      // 6 temp Matrices at once should be enough
     }
 }
-
-

src/Mesh/babylon.groundMesh.ts

@@ -1,4 +1,4 @@
-module BABYLON {
+module BABYLON {
     export class GroundMesh extends Mesh {
         public generateOctree = false;
 
@@ -42,6 +42,7 @@
                 return this.position.y;
             }
             if (!this._heightQuads || this._heightQuads.length == 0) {
+                this._initHeightQuads();
                 this._computeHeightQuads();
             }
             var facet = this._getFacetAt(x, z);
@@ -78,6 +79,7 @@
                 return;
             }
             if (!this._heightQuads || this._heightQuads.length == 0) {
+                this._initHeightQuads();
                 this._computeHeightQuads();
             }
             var facet = this._getFacetAt(x, z);
@@ -86,6 +88,18 @@
             ref.z = facet.z;
         }
 
+        /**
+        * Force the heights to be recomputed for getHeightAtCoordinates() or getNormalAtCoordinates()
+        * if the ground has been updated.
+        * This can be used in the render loop
+        */
+        public updateCoordinateHeights(): void {
+            if (!this._heightQuads || this._heightQuads.length == 0) {
+                this._initHeightQuads();
+            }
+            this._computeHeightQuads();
+        }
+
         // Returns the element "facet" from the heightQuads array relative to (x, z) local coordinates
         private _getFacetAt(x: number, z: number): Vector4 {
             // retrieve col and row from x, z coordinates in the ground local system
@@ -101,23 +115,36 @@
             return facet;
         }
 
-        // Populates the heightMap array with "facet" elements :
+        //  Creates and populates the heightMap array with "facet" elements :
         // a quad is two triangular facets separated by a slope, so a "facet" element is 1 slope + 2 facets
         // slope : Vector2(c, h) = 2D diagonal line equation setting appart two triangular facets in a quad : z = cx + h
         // facet1 : Vector4(a, b, c, d) = first facet 3D plane equation : ax + by + cz + d = 0
         // facet2 :  Vector4(a, b, c, d) = second facet 3D plane equation : ax + by + cz + d = 0
-        private _computeHeightQuads(): void {
+        private _initHeightQuads(): void {
             this._heightQuads = new Array();
+            for (var row = 0; row < this._subdivisions; row++) {
+                for (var col = 0; col < this._subdivisions; col++) {
+                    var quad = { slope: BABYLON.Vector2.Zero(), facet1: new BABYLON.Vector4(0, 0, 0,0), facet2: new BABYLON.Vector4(0, 0, 0,0) };
+                    this._heightQuads[row * this._subdivisions + col] = quad;
+                }
+            }
+        }
+
+        // Compute each quad element values and update the the heightMap array :
+        // slope : Vector2(c, h) = 2D diagonal line equation setting appart two triangular facets in a quad : z = cx + h
+        // facet1 : Vector4(a, b, c, d) = first facet 3D plane equation : ax + by + cz + d = 0
+        // facet2 :  Vector4(a, b, c, d) = second facet 3D plane equation : ax + by + cz + d = 0
+        private _computeHeightQuads(): void {
             var positions = this.getVerticesData(VertexBuffer.PositionKind);
-            var v1 = Vector3.Zero();
-            var v2 = Vector3.Zero();
-            var v3 = Vector3.Zero();
-            var v4 = Vector3.Zero();
-            var v1v2 = Vector3.Zero();
-            var v1v3 = Vector3.Zero();
-            var v1v4 = Vector3.Zero();
-            var norm1 = Vector3.Zero();
-            var norm2 = Vector3.Zero();
+            var v1 = Tmp.Vector3[0];
+            var v2 = Tmp.Vector3[1];
+            var v3 = Tmp.Vector3[2];
+            var v4 = Tmp.Vector3[3];
+            var v1v2 = Tmp.Vector3[4];
+            var v1v3 = Tmp.Vector3[5];
+            var v1v4 = Tmp.Vector3[6];
+            var norm1 = Tmp.Vector3[7];
+            var norm2 = Tmp.Vector3[8];
             var i = 0;
             var j = 0;
             var k = 0;
@@ -147,7 +174,6 @@
                     // 2D slope V1V4
                     cd = (v4.z - v1.z) / (v4.x - v1.x);
                     h = v1.z - cd * v1.x;             // v1 belongs to the slope
-                    var slope = new Vector2(cd, h);
 
                     // facet equations :
                     // we compute each facet normal vector
@@ -163,14 +189,13 @@
                     norm2.normalize();
                     d1 = -(norm1.x * v1.x + norm1.y * v1.y + norm1.z * v1.z);
                     d2 = -(norm2.x * v2.x + norm2.y * v2.y + norm2.z * v2.z);
-                    var facet1 = new BABYLON.Vector4(norm1.x, norm1.y, norm1.z, d1);
-                    var facet2 = new BABYLON.Vector4(norm2.x, norm2.y, norm2.z, d2);
 
-                    var quad = { slope: slope, facet1: facet1, facet2: facet2 };
-                    this._heightQuads.push(quad);
+                    var quad = this._heightQuads[row * this._subdivisions + col];
+                    quad.slope.copyFromFloats(cd, h);
+                    quad.facet1.copyFromFloats(norm1.x, norm1.y, norm1.z, d1);
+                    quad.facet2.copyFromFloats(norm2.x, norm2.y, norm2.z, d2);
                 }
             }
         }
     }
 }
-