SCNCamera should set zNear and zFar to show full scene

[XanderXu]

Describe the bug In Lsystem3DView's generateScene func, add the SCNCamera, but use the default zNear(1m) and zFar(100m).

But it's too small, can't show the full plant, the scene has been clipped, can't see the far part.

Platform (please complete the following information): iOS 14

Additional context set zNear and zFar to camera should be ok

cameraNode.camera?.zNear = 0.1
cameraNode.camera?.zFar = 1000