fix typos

src/Math/babylon.math.ts

@@ -2602,8 +2602,8 @@ module BABYLON {
             nearScreenSource.y = -(sourceY / viewportHeight * 2 - 1);
             nearScreenSource.z = -1.0;
             var farScreenSource = MathTmp.Vector3[1].copyFromFloats(nearScreenSource.x, nearScreenSource.y, 1.0);
-            const nearVec3 = MathTmp.Vector3[3];
-            const farVec3 = MathTmp.Vector3[4];
+            const nearVec3 = MathTmp.Vector3[2];
+            const farVec3 = MathTmp.Vector3[3];
             Vector3.UnprojectFromInvertedMatrixToRef(nearScreenSource, matrix, nearVec3);
             Vector3.UnprojectFromInvertedMatrixToRef(farScreenSource, matrix, farVec3);
 

src/babylon.scene.ts

@@ -5079,7 +5079,7 @@ module BABYLON {
             x = x / this._engine.getHardwareScalingLevel() - viewport.x;
             y = y / this._engine.getHardwareScalingLevel() - (this._engine.getRenderHeight() - viewport.y - viewport.height);
 
-            result.update(x, y, viewport.width, viewport.height, world ? world : Matrix.IdentityReadOnly(), cameraViewSpace ? Matrix.IdentityReadOnly() : camera.getViewMatrix(), camera.getProjectionMatrix());
+            result.update(x, y, viewport.width, viewport.height, world ? world : Matrix.IdentityReadOnly, cameraViewSpace ? Matrix.IdentityReadOnly : camera.getViewMatrix(), camera.getProjectionMatrix());
             return this;
         }