Originally posted by Falott what Radical Edward says is: your frog mesh is not a closed mesh. imagine a sphere. a sphere is closed geometry. cut it in halfs and delete one half. now you have a open mesh. your frogMesh is open. that´s why boolean doesn´t work. just to remind you 1) first of all - allways make sure you have no nonmanifold geomtry where you want to apply a boolean operation onto. 2) both geometries must be closed meshes. and with closed i mean really watertight. 3) conform distribution of normals on the surface. all normals of both geometries must point outwards or inwards at the same time. reading the manual might help too. I sewed the back of it up (and the eye just to be safe) and it didnÕt work. I created 2 nurbs spheres, cut them both in half, and then did booleans>union and it worked. So my problem isnÕt because it isnÕt a closed surface, itÕs something else. :headbang: I can email you the file if you want to look at it.