Planes and working with 3d mesh data

Hi Group

is there any really good tutorial / demo videos on using and controlling cplanes / sketch planes in rhino 6?
I want to totally understand and control them in all ways and on all surfaces, meshes etc…
currently i want to be able to set up a sketch plane on or in front of a 3d Mesh file section so i can make a sketch then extrude that sketch through the mesh data and make a cutout so i can then work on it. so any methods of controlling sketch plans with meshes will really help.
I have attached a picture of a 3d scan mesh with the textures applied in rhino 6, you will see a green line that I have sketched on the mesh surface which is tracing round pen marks on the mesh texture that I need to cut out. but ideally, I would like to make a flat sketch on a sketch plane not a wobbly 3d sketch on the mesh scan. I hope that makes sense)

I have used Rhino for years but mainly for 2d work and quick visualization of 3d files. (I have other packages that I work in on 3d work) so i have not really needed to place sketch planes in weird places…

I would like to learn more on this if anyone can point me in the right direction.

A

“Sketch planes” are called CPlanes in Rhino, and you can create them in many different ways. There is some info in the Help here:

http://docs.mcneel.com/rhino/6/help/en-us/index.htm#commands/cplane.htm?Highlight=CPlane

The user manual does not seem to cover CPlanes extensively though.

Thankyou for your reply, i will try to find some videos on youtube as well.

regards A