setDetailFromDistance aspect ratio friendly adjustment

Engine/source/ts/tsShapeInstance.cpp

@@ -593,7 +593,7 @@ S32 TSShapeInstance::setDetailFromDistance( const SceneRenderState *state, F32 s
    // 4:3 aspect ratio, we've changed the reference value
    // to 300 to be more compatible with legacy shapes.
    //
-   const F32 pixelScale = state->getViewport().extent.y / 300.0f;
+   const F32 pixelScale = (state->getViewport().extent.x / state->getViewport().extent.y);
 
    // This is legacy DTS support for older "multires" based
    // meshes.  The original crossbow weapon uses this.