Add method to collect viewport water contact patches

src/viewport-three/viewport-host.ts

@@ -2989,6 +2989,55 @@ export class ViewportHost {
 
     cachedTexture?.texture.dispose();
 
+      private collectViewportWaterContactPatches(
+        document: SceneDocument,
+        excludedBrushId: string,
+        center: Vec3,
+        rotationDegrees: Vec3,
+        size: Vec3
+      ) {
+        const contactBounds: GeneratedColliderBounds[] = [];
+
+        for (const brush of Object.values(document.brushes)) {
+          if (brush.id === excludedBrushId || brush.volume.mode !== "none") {
+            continue;
+          }
+
+          contactBounds.push(getBoxBrushBounds(brush));
+        }
+
+        for (const modelInstance of getModelInstances(document.modelInstances)) {
+          if (modelInstance.collision.mode === "none") {
+            continue;
+          }
+
+          const asset = this.projectAssets[modelInstance.assetId];
+
+          if (asset?.kind !== "model") {
+            continue;
+          }
+
+          try {
+            const generatedCollider = buildGeneratedModelCollider(modelInstance, asset, this.loadedModelAssets[modelInstance.assetId]);
+
+            if (generatedCollider !== null) {
+              contactBounds.push(generatedCollider.worldBounds);
+            }
+          } catch {
+            // Validation already surfaces unsupported collider modes; the viewport keeps rendering.
+          }
+        }
+
+        return collectWaterContactPatches(
+          {
+            center,
+            rotationDegrees,
+            size
+          },
+          contactBounds
+        );
+      }
+
     const texture = createStarterMaterialTexture(material);
 
     this.materialTextureCache.set(material.id, {