Trackpad excersise anyone?

has anyone worked through this trackpad excersise on level 2?


I am assuming a lot of it is guess work… such as how high to raise the ends of the outer curve shape? to design the left and right elispe detail?.. Iv been trying to adjust the outer curve through ‘adding points’ then adjusting with gumball (not shown in model as I deleted again…)… and then using a ‘rail revolve’ to cover from a central 3.4cm height axis in the middle… (with a conic curve leading from the outer rail. I have also tried lofting but for some reason it doesnt like it. I also have struggled to make the conic curve shape ‘join’ to the rail… I glanced at an image on vimeo… ( this was all i could find)… and it appeared that the outer edge was raised all along rather that just at front and back. Am just a bit confused how to proceed as I keep having to start again. If anyone could spare a minute and just advise how they would go about this that would be really great. Slow learning but getting there. Thanks! Ashley

TRACKBALLcm.3dm (3.4 MB)

There are no learning resources except this forum and im stuck…

Hi Ashley - this ‘exercise’ is actually a sort of warm-up for classroom classes, it is intended to help the instructor roughly asses the experience of the students - so it is deliberately left unexplained…


yeh… I know… I was wondering if I could get opinions on it as development… since this forum is where your team have been persistently been telling me to come… .and yes, ive covered the material. Just simply, rather than closing doors on me and my attempts, it would have been really helpful if mcneel tec/training had sent me the correct classroom offers/videos in the first place since I have tried so many times to look for guided support., so I hadnt spend nearly 3 months faffing around on my own. but hey.

I have them now after speaking Mary, so will now be doing the guided sessions… …just would have been good to get this in March when I first contacted you and told you i was looking to learn.

if you are looking for any advices on how to model what you have shown then just simply ask for it and if it has to be, again and again. swinging the sceptre at people does not make you a better modeller :smiley:

anyway the keywords to creating this U.F.O trackpad for example are some outlines then network surface. you can create the outlines of the buttons as a flat on the cplane and simply extrude them to use as a split object on the network surface or however you created the main shape. you can also use InterpCrvOnSrf to draw any shape directly on a surface and split the buttons out.

if you need it and havent thought of the exact shape before, you can achieve the round edges if you have 2 surfaces joined and use fillet edge on them. alternately you can also use 2 different surface slightly apart from each other and use blend surface with both and join them. there are several ways to achieve this. your key is to try as many as you can to see what you want to use rather i would suggest.


edit: i would recreate your bottom part to simple curves, if possible always create a closed curve in one go, rather then joining multiple curves into a bigger, this will help you creating smoother lofts sweeps whatever you need.

here some detail, may not be a beauty and i leave the ball to you, but is being achieved by splitting off then either you make a pipe around the curve make boolean subtraction or you make it manually with offset curve on surface split the rest off and offset the buttons without solid and blend them together with blend surface which gives you a better control over how they round up.

Hi Ashley - in case it helps, here is how I’d do this, as a quick ‘design it as you go’ simple construction.

TrackBallBody.3dm (228.0 KB)


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Thankyou! I only swing a soft inflatable sceptre about sometimes, on occasion when im feeling stuck and annoyed… Its harmless… and I appreciate the effort in replying. Ill have a look at this in a bit again when Ive finished the session im in. thanks :slight_smile:

Ah thanks… ill have a look at this again shortly. Appreciate it

here you go an inflatable sceptre for the hopefully not so inflatable queen :wink:
may it help in moments when you feel stuck :smile:

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pahaha… if only I could have made that myself!

… Its the same commands that are holding me up… I get the principal but I cant seem to loft or rail sweep… (except in the excerises when they are easy). I dont understand the principals that allow a loft or sweep. ie. Do ALL curves have to join. Does there have to be a set number or a cross section curve over the rail. .Does the axis on a revolve rail have to be level with the plane etc. I get the idea but every model I make falls at this first hurdle! I looked at your step by step… (ignore the wonky lemon shape for now)… and i tried to ‘loft’ and this happens; ill attache another model to show the same principal… that i cant create a loft surface… PENDANT1.3dm (3.3 MB)

Mashed up lemon.3dm (3.3 MB)

Hi Asley - Loft only takes curves in one direction - leave out the cross-section curve for Loft, leave it in for NetworkSrf


Hi Ashley,
This is regarding the pendant.
Your curves are very good.

I recommend:

  • Explode the curves
  • Do not use Loft (not enough control)
  • Use the EdgeSrf on all the sections except the middle
  • In the middle area, create an additional cross section curve
  • Use the Sweep2 in the middle area
  • Join together and Cap.
    See the video here
    For the record, this is the way I would do this. There are many other approaches, I am sure.

Mary Ann Fugier

Thanks Mary,… this is really helpful. I have managed to get a bit of control on edgesrf and sweep now…Could you/anyone advise on this other trackpad model again?.. I really want to get it better. Im redoing the skeleton curves again… and I want to create a nice soft curve at the pointy join where i mirrored the two sides. I have pulled up the corners initially on first curve, but then if I mirror it and add the surface it pulls into a crease… and I want this nice and smooth.

I am trying to master the fillet commands here to soften… but I am jsut guessing at the angle and also if this command works on open or closed curves… or if its a fillet curve or corner that i need?.. TRACKPAD-VERSIONMILLION.3dm (4.0 MB)

PASCAL… Thanks for this… I am looking and there is no way I can understand what that means. You say to ‘loft…’ but there is no lofting visable in your image… you also have created a raised border under the instruction ‘trim’ from right view. But I have no idea how that works in real terms… How did you get that raised edge? I have tried to draw a curve and raise the edges in my attempt by using gumball and picking up corners in a basic kind of way. But how did you use trim to get that line?? Or is that not what you meant? I want to get nice lines like that…

Hi Ashley - the surface I created from the three curves is a Loft surface (Green) . The red curve is used to trim the loft surface - and sorry, the Front view is what you need - apologies - the FRONT view. The cyan angled surface is also a Loft surface,
TrackBallBody.3dm (227.8 KB)


OH!!! did you draw a red line in the front view and use it to trim the whole shape??? Like a wirecut? I see… ok ill try that next time… can you please look at my curves and tell me (in addition to your way…) what I am doing wrong that makes this simple shape not actually surface without pulling?.. I follwoed the instructions tTRACKPAD-VERSIONMILLION.3dm (4.0 MB)
o do ‘one big curve’ rather than conics… but now I cant use the edge srf or explode. Instead I tried to break my curve up by using split… but it wont… Whats wrong with my version that none of the coomands work?..

Hi Ashley - the approach is understandable, but generally not the best when working with surfaces - it looks like you are trying to build the details into the input curves - that can work in some cases but more often it is more controllable and cleaner to add things like fillets after the fact and build your shapes from simple surfaces. As you can see, with the ‘lifted’ ends and the details at the ends of your curves in place, it is very hard to get good control of the basic surface. In my example, the input curves are simple and clean and the resulting surface very clean- no wobbles or lumps and bumps. Adding the bottom cut - the trim to get the roundy bottom shape and the fillets, does not affect the cleanliness of this initial surface, they are all added operations if you see what I mean.

It is useful to sort of mentally break up a shape into ‘primary’ and ‘secondary’ or ‘transition’ surfaces (like blends and fillets or some equivalent) and build accordingly rather than try to do more in complicated surfaces. Usually.


u r the best :slight_smile: thanks Pascal. Ill start again using your method… Ill get there in the end…