diff --git a/zine-constants.js b/zine-constants.js
index 29735bb..9d03749 100644
--- a/zine-constants.js
+++ b/zine-constants.js
@@ -1,9 +1,11 @@
 export const panelSize = 1024;
 
+export const pointCloudPositionalStride = 4 + 4 + 4;
+export const pointCloudFullStride = pointCloudPositionalStride + 1 + 1 + 1;
+
 export const floorNetWorldSize = 100;
 export const floorNetWorldDepth = 1000;
 export const floorNetResolution = 0.1;
 export const floorNetPixelSize = floorNetWorldSize / floorNetResolution;
 
-export const pointcloudStride = 4 + 4 + 4 + 1 + 1 + 1;
 export const physicsPixelStride = 8;
diff --git a/zine-geometry-utils.js b/zine-geometry-utils.js
index 419572d..d98f059 100644
--- a/zine-geometry-utils.js
+++ b/zine-geometry-utils.js
@@ -1,7 +1,5 @@
 import * as THREE from 'three';
-import {
-  pointcloudStride,
-} from './zine-constants.js';
+import { pointCloudPositionalStride } from './zine-constants.js';
 
 //
 
@@ -18,9 +16,9 @@ function pointCloudArrayBufferToPositionAttributeArray(
   pixelStride = 1,
 ) { // result in float32Array
   const dataView = new DataView(arrayBuffer);
-  for (let i = 0, j = 0; i < arrayBuffer.byteLength; i += pointcloudStride) {
+  for (let i = 0, j = 0; i < arrayBuffer.byteLength; i += pointCloudPositionalStride) {
     if (pixelStride !== 1) {
-      const i2 = i / pointcloudStride;
+      const i2 = i / pointCloudPositionalStride;
       const sx = i2 % width;
       const sy = Math.floor(i2 / width);
       if (sx % pixelStride !== 0 || sy % pixelStride !== 0) { // skip non-stride points
@@ -138,6 +136,32 @@ export function depthFloat32ArrayToGeometry(
 
 //
 
+export function getDepthFloat32ArrayWorldPositionPx(
+  depthFloat32Array,
+  px,
+  py,
+  width,
+  height,
+  camera,
+  scale,
+  target
+) {
+  px = Math.min(Math.max(px, 0), width - 1);
+  py = Math.min(Math.max(py, 0), height - 1);
+
+  let x = px / width;
+  let y = py / height;
+
+  const i = py * width + px;
+  y = 1 - y;
+
+  const viewZ = depthFloat32Array[i];
+  const worldPoint = setCameraViewPositionFromViewZ(x, y, viewZ, camera, target);
+  worldPoint.multiply(scale);
+  worldPoint.applyMatrix4(camera.matrixWorld);
+  return target;
+}
+
 export function getDepthFloat32ArrayWorldPosition(
   depthFloat32Array,
   x, // 0..1
@@ -289,8 +313,12 @@ export const snapPointCloudToCamera = (pointCloudArrayBuffer, width, height, cam
 
   const scaleFactor = 1 / width;
   const dataView = new DataView(pointCloudArrayBuffer);
-  for (let i = 0; i < pointCloudArrayBuffer.byteLength; i += pointcloudStride) {
-    let x = dataView.getFloat32(i + 0, true);
+  for (
+    let i = 0;
+    i < pointCloudArrayBuffer.byteLength;
+    i += pointCloudPositionalStride
+  ) {
+    let x = dataView.getFloat32(i    , true);
     let y = dataView.getFloat32(i + 4, true);
     let z = dataView.getFloat32(i + 8, true);
 
@@ -413,8 +441,6 @@ export const setCameraViewPositionFromOrthographicViewZ = (x, y, viewZ, camera,
   return target;
 }
 
-//
-
 export const getDoubleSidedGeometry = geometry => {
   const geometry2 = geometry.clone();
   // double-side the geometry
@@ -452,4 +478,4 @@ export const getGeometryHeights = (geometry, width, height, heightfieldScale) =>
     }
   }
   return heights;
-};
\ No newline at end of file
+};
diff --git a/zine-renderer.js b/zine-renderer.js
index 423d91e..6febc79 100644
--- a/zine-renderer.js
+++ b/zine-renderer.js
@@ -19,7 +19,7 @@ import {
 } from './zine-camera-utils.js';
 import {
   floorNetPixelSize,
-  pointcloudStride,
+  pointCloudPositionalStride,
   physicsPixelStride,
 } from './zine-constants.js';
 
@@ -218,9 +218,9 @@ class ScenePhysicsMesh extends THREE.Mesh {
     // }
     const arrayBuffer = pointCloudArrayBuffer;
     const pixelStride = physicsPixelStride;
-    for (let i = 0, j = 0; i < arrayBuffer.byteLength; i += pointcloudStride) {
+    for (let i = 0, j = 0; i < arrayBuffer.byteLength; i += pointCloudPositionalStride) {
       if (pixelStride !== 1) {
-        const i2 = i / pointcloudStride;
+        const i2 = i / pointCloudPositionalStride;
         const sx = i2 % width;
         const sy = Math.floor(i2 / width);
         if (sx % pixelStride !== 0 || sy % pixelStride !== 0) { // skip non-stride points
@@ -228,7 +228,7 @@ class ScenePhysicsMesh extends THREE.Mesh {
         }
       }
 
-      const s = segmentSpecs.array[i / pointcloudStride];
+      const s = segmentSpecs.array[i / pointCloudPositionalStride];
       segments[j] = s;
 
       j++;
@@ -544,4 +544,4 @@ export class ZineRenderer extends EventTarget {
       );
     targetZineRenderer.camera.updateMatrixWorld();
   }
-}
\ No newline at end of file
+}