problem description
 can viewer be cut by model? For example, if three models are loaded in viewer at the same time, I will cut the model three times: 
 1, the first cut is z-direction, and the first model is the first model, but the second model and the third model will not be cut off by this z-direction. 
 2. The second cut is x-direction, and the second model is cut, but the first and third models will not be cut off by this x-direction. 
 3. The third model is cut in the y direction for the third cut, but the first and second models are not cut off by this x direction. 
