The bounds to check against when intersecting the scene is now being properly expanded and 0 sized component bounds are being taken care of (#3450)

packages/viewer-sandbox/src/main.ts

@@ -447,6 +447,9 @@ const getStream = () => {
 
     // Far away house section tool
     // 'https://app.speckle.systems/projects/817c4e8daa/models/f0601ef5f9@80db5ff26a'
+
+    // Perfectly flat
+    // 'https://app.speckle.systems/projects/344f803f81/models/5582ab673e'
   )
 }
 

packages/viewer/src/modules/Intersections.ts

@@ -17,6 +17,7 @@ import {
   SpeckleRaycaster
 } from './objects/SpeckleRaycaster.js'
 import { ObjectLayers } from '../IViewer.js'
+import { World } from './World.js'
 
 export class Intersections {
   protected raycaster: SpeckleRaycaster
@@ -197,21 +198,13 @@ export class Intersections {
         return a.distance - b.distance
       })
     if (bounds) {
-      this.boundsBuffer.copy(bounds)
       /** We slightly increase the tested bounds to account for fp precision issues which
        *  have proven to arise exactly at the edge of the bounds. Our BVH returns intersection
        *  points ever so slightly off the actual surface, so for very thin geometries it might
        *  fall outside of the bounds
        */
-      const offsetSize = new Vector3(
-        0.001 * (this.boundsBuffer.max.x - this.boundsBuffer.min.x),
-        0.001 * (this.boundsBuffer.max.y - this.boundsBuffer.min.y),
-        0.001 * (this.boundsBuffer.max.z - this.boundsBuffer.min.z)
-      )
+      this.boundsBuffer.copy(World.expandBoxRelative(bounds))
 
-      this.boundsBuffer.expandByVector(
-        new Vector3(offsetSize.x, offsetSize.y, offsetSize.z)
-      )
       results = results.filter((result) => {
         return (
           this.boundsBuffer.containsPoint(result.point) ||

packages/viewer/src/modules/World.ts

@@ -98,4 +98,31 @@ export class World {
     offsetBox.applyMatrix4(MatBuff1)
     return offsetBox
   }
+
+  public static expandBoxRelative(box: Box3, offsetAmount: number = 0.001) {
+    const center = box.getCenter(new Vector3())
+    const size = box.getSize(new Vector3())
+    MatBuff1.makeTranslation(center.x, center.y, center.z)
+    MatBuff2.copy(MatBuff1).invert()
+    MatBuff0.identity()
+    MatBuff0.makeScale(1 + offsetAmount, 1 + offsetAmount, 1 + offsetAmount)
+    const offsetBox = new Box3().copy(box)
+    if (size.x === 0) {
+      offsetBox.min.x += -offsetAmount * 0.5
+      offsetBox.max.x += offsetAmount * 0.5
+    }
+    if (size.y === 0) {
+      offsetBox.min.y += -offsetAmount * 0.5
+      offsetBox.max.y += offsetAmount * 0.5
+    }
+    if (size.z === 0) {
+      offsetBox.min.z += -offsetAmount * 0.5
+      offsetBox.max.z += offsetAmount * 0.5
+    }
+    offsetBox.applyMatrix4(MatBuff2)
+    offsetBox.applyMatrix4(MatBuff0)
+    offsetBox.applyMatrix4(MatBuff1)
+
+    return offsetBox
+  }
 }