diff --git a/lib/torque/leaflet/torque.js b/lib/torque/leaflet/torque.js
index 17452bf..9ec4d32 100644
--- a/lib/torque/leaflet/torque.js
+++ b/lib/torque/leaflet/torque.js
@@ -231,6 +231,12 @@ L.TorqueLayer = L.CanvasLayer.extend({
       this.renderer.firstTileCoords = {coord: this._tiles[min.k].coord, pos:this.getTilePos(this._tiles[min.k].coord)};
       ctx.setTransform(1, 0, 0, 1, this.renderer.firstTileCoords.pos.x, this.renderer.firstTileCoords.pos.y);
 
+      var valsPerTile = 256/this.options.resolution;
+      this.renderer.globalGrid = Array.apply(null, Array(this.renderer.tileDimensions.h * valsPerTile)).map(Number.prototype.valueOf,0);
+      for (var i = 0; i < this.renderer.globalGrid.length; i++){
+        this.renderer.globalGrid[i] = Array.apply(null, Array(this.renderer.tileDimensions.w * valsPerTile)).map(Number.prototype.valueOf,0);
+      }
+
       for(t in this._tiles) {
         tile = this._tiles[t];
         if (tile) {
diff --git a/lib/torque/renderer/point.js b/lib/torque/renderer/point.js
index b4020e3..a85d4a8 100644
--- a/lib/torque/renderer/point.js
+++ b/lib/torque/renderer/point.js
@@ -215,23 +215,15 @@ var contour = require('./contour');
 
     _gridData: function(tile){
       var valsPerTile = this.TILE_SIZE/this.options.resolution;
+      // baseIndex is the distance to the upper left corner of the grid, in cells
       var baseIndex = {
         x: (tile.coord.x - this.firstTileCoords.coord.x) * valsPerTile,
         y: (tile.coord.y - this.firstTileCoords.coord.y) * valsPerTile
       }
 
-      this.globalGrid = Array.apply(null, Array(this.tileDimensions.h * valsPerTile)).map(Number.prototype.valueOf,0);
-      for (var i = 0; i < this.globalGrid.length; i++){
-        this.globalGrid[i] = Array.apply(null, Array(this.tileDimensions.w * valsPerTile)).map(Number.prototype.valueOf,0);
-      }
-
-      // to do invert
-      for(var i =0; i < tile.renderData.length; i++){
+      for(var i = 0; i < tile.renderData.length; i++){
         var x = tile.x[i], y = tile.y[i];
-        if(!this.globalGrid[baseIndex.y + y/this.options.resolution]){
-          this.globalGrid[baseIndex.y + y/this.options.resolution] = [];
-        }
-        this.globalGrid[baseIndex.y + y/this.options.resolution][baseIndex.y + x/this.options.resolution] = tile.renderData[i];
+        this.globalGrid[baseIndex.y + (256 - y)/this.options.resolution-1][baseIndex.x + x/this.options.resolution] = tile.renderData[i];
       }
     },