Arguments

tinEname1  (ename or vla-object)  the first TinSurface entity
tinEname2  (ename or vla-object)  the second TinSurface entity
clipEnt  (ename or vla-object)  the clipping entity
midOrdinateDist  (number)  specifies the smoothness (it is the distance of the surface at the mid of the ordinate between 2 rasterised points, in drawing units)

Return

(ename)  TinVolumeSurface entity, or NIL

Example

(tinvs:createby2surfacesandentity tin1 tin2 (entlast) 0.2)
<Entity name: 48f52a90>

Remarks

the 'midOrdinateDistance' is the distance of the curve's midpoint, to the arc center; similar to arc's bulge; used as a kind of tolerance;
see https://civil3dplus.wordpress.com/2012/12/23/surfaces-and-the-mid-ordinate-distance/
typical values are in range : 0.01 - 0.05 (meter), 0.5 - 1.0 (inch)