Update BuildVolume and ConvexHullNode to use new API

resources/shaders/grid.shader

@@ -0,0 +1,39 @@
+[shaders]
+vertex =
+    uniform highp mat4 u_modelViewProjectionMatrix;
+
+    attribute highp vec4 a_vertex;
+    attribute lowp vec2 a_uvs;
+
+    varying lowp vec2 v_uvs;
+
+    void main()
+    {
+        gl_Position = u_modelViewProjectionMatrix * a_vertex;
+        v_uvs = a_uvs;
+    }
+
+fragment =
+    uniform lowp vec4 u_gridColor0;
+    uniform lowp vec4 u_gridColor1;
+
+    varying lowp vec2 v_uvs;
+
+    void main()
+    {
+        if (mod(floor(v_uvs.x / 10.0) - floor(v_uvs.y / 10.0), 2.0) < 1.0)
+            gl_FragColor = u_gridColor0;
+        else
+            gl_FragColor = u_gridColor1;
+    }
+
+[defaults]
+u_gridColor0 = [0.96, 0.96, 0.96, 1.0]
+u_gridColor1 = [0.8, 0.8, 0.8, 1.0]
+
+[bindings]
+u_modelViewProjectionMatrix = model_view_projection_matrix
+
+[attributes]
+a_vertex = vertex
+a_uvs = uv0