Modeling a scoop

I’m working on the Level 2 tutorials, Section 9 “an approach to modeling”. I’ve opened Scoop 003 to make the sides of the cutout. I thought I was following the instructions as written but, I’m not getting the results I expected. The instructions seem a little vague. My extended surface doesn’t go in the direction it should. Can anyone tell me what I’m doing wrong? Thanks!

Please post your .3dm file. Drag the file into the panel where you type. Or use the “upload” symbol, arrow point up above a bar, which is at the top of the panel where you type.

That’s an image of your file. You need to upload and post the Rhino .3dm file itself so someone can open it and examine your geometry.

So far it looks correct but you don’t need that vertical surface off the ‘front’ edge of the green surface - toss that.


The image at the top of this page is my file.

That’s what I got when I tried to extend the edge. It’s supposed to be horizontal with the front edge of the green surface.

Hi James - why did you want to extend the edge? BTW, in some editions of the Level 2 material, it may say to extrude tapered the outer projected curve - that is not correct, it is the inner curve you extrude to get the blue surface.


Why does the illustration in the tutorials show the forward edge of the upper surface being extended? The entire section of tutorials for exercise 24 - Cutout “An approach to modeling” is too confusing.
I’ve gone through the tutorial about a dozen times. Nothing seems to work right. It is becoming very frustrating to read the instructions over and over but, not getting anything to right. I think someone at Rhino should examine exercise 24 and edit it so that someone that is trying to learn the program won’t become frustrated enough to just give up. Thanks for your time and effort! Hasn’t anyone else complained about this particular exercise?

Hi James - it does not. If you follow the steps, you should have a small piece of the main starting surface at that location - it is not an extension of the ‘floor’ surface but a surface to which that floor surface is to be MatchSrf-ed for Curvature. It is trimmed out from a copy of the original in the first few steps. Do you see that?
This is a pretty involved exercise - really designed for in-classroom use, primarily, but I don’t think it is as hard to follow as all that. That said, I’ll review it and see if we can make it better for on-your-own learning.


Thanks! Either the tutorial is incorrect or I’m not following or understanding it properly. It is a very difficult exercise and I would like to get a full understanding of what has to be done. I’ll keep at it until I get it or, lose patience and give up for a while.

Here’s the thinking: The ‘floor’ of the scoop must blend seamlessly and gracefully with the starting surface. The exact shape of this floor surface is ultimately up to you but the idea is to make an imperceptible transition at the front end. To do this MatchSrf is an obvious tool to use, but that requires an edge to match to. So, a little piece of the surface to match to is chopped out so that it can provide an edge at the required location and yet be identical to the main surface at that location.


That makes sense. I’ll keep at it. Have a good weekend!

where can i find or buy this tutorial book or cd or video ??
greetings Peter

Hi Peter,

It’s in the Level2 training fro Rhino5.
It can downloaded here:


thanks guys-:slight_smile:
greetings Peter