This is my model in the solid view, we can see it is complete.
but in the render view or in the final render it is clipped :
here is my viewport clipping settings :
I have added a cube to the object in edit mode ; the render shows me all the form but not the cube!!!! as you can see
I added to the object (in edit form) a cube and move it far away. Now the render shows all the form as if the new mesh is moving some clipping plane...