Rhino viewport display errors

Hi,I came across a strange problems of Rhino Display .I feel puzzled and I hope that there can be someone to help me.
Just as the images showe.
The object will be clipped when I move the camera close to it though I did not use the section tool
And planes looks strange, just like many triangles–but I’m sure that these strange objects are just some solid extruded from curves (and then Unioned)

I’m not a native English speaker.So please forgive me if anything I spoke went wrong or strange.
I’m troubled for hours and no solution can be found (lol)

The camera has a clipping plane to view the inside of objects. There isn’t much that can be done besides backing up the camera.

Hello - can you post a screen shot in Wireframe?


Actually the problem that it looks like hundreds of triangles disappeared when I change the unit from meter to millimeter.But the problem of clipping too earlier remains and puzzled me a lot.It seems that in other 3d software like blender, the distance at which the clipping begins can be changed.But I don’t know how to make it in Rhino