From 6df1c6bb5cf2eb2032588f80d708ad3290893c1a Mon Sep 17 00:00:00 2001
From: David Catuhe <david.catuhe@live.fr>
Date: Thu, 24 Oct 2024 11:06:42 -0700
Subject: [PATCH] Add warning when detecting negative genus (#15736)

* Add warning when detecting negative genus

* revert unwanted changes

* .

* .
---
 packages/dev/core/src/Meshes/csg2.ts | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/packages/dev/core/src/Meshes/csg2.ts b/packages/dev/core/src/Meshes/csg2.ts
index e480448ce83..26321bba678 100644
--- a/packages/dev/core/src/Meshes/csg2.ts
+++ b/packages/dev/core/src/Meshes/csg2.ts
@@ -119,7 +119,7 @@ export class CSG2 implements IDisposable {
 
     private _process(operation: "difference" | "intersection" | "union", csg: CSG2) {
         if (this.numProp !== csg.numProp) {
-            throw new Error("CSG must have the same number of properties");
+            throw new Error("CSG must be used with geometries having the same number of properties");
         }
         return new CSG2(Manifold[operation](this._manifold, csg._manifold), this.numProp, this._vertexStructure);
     }
@@ -301,11 +301,18 @@ export class CSG2 implements IDisposable {
         const manifoldMesh = new ManifoldMesh({ numProp: numProp, vertProperties, triVerts, runIndex, runOriginalID });
         manifoldMesh.merge();
 
+        let returnValue: CSG2;
         try {
-            return new CSG2(new Manifold(manifoldMesh), numProp, structure);
+            returnValue = new CSG2(new Manifold(manifoldMesh), numProp, structure);
         } catch (e) {
             throw new Error("Error while creating the CSG: " + e.message);
         }
+
+        if (returnValue._manifold.genus() < 0) {
+            throw new Error("Incorrect volume detected. Make sure you are not using a double sided geometry");
+        }
+
+        return returnValue;
     }
 
     private static _Construct(data: IVertexDataLike, worldMatrix: Nullable<Matrix>, runIndex?: Uint32Array, runOriginalID?: Uint32Array) {