[HELP] Modeling Complex Angles in Stud.io

[JLiu15]

Hey guys, I'm a beginner to digital building, and I'm trying to make one of my recent MOCs in stud.io and make instructions for it. However, I'm not sure how to model a structure that has plenty of connections at non-right angles. I know you can rotate a piece or a structure 90 degrees using the arrow keys or rotate it about an axis for a given number of degrees, but solving for the exact angle those connections are at would take A LOT of complex trigonometry. Even then, the angles won't be 100% precise.

I've taken a look at some tutorials and played around with the controls, but I haven't figured out how to connect pieces at the angle they'd sit at when connected in real life. So far I've used the "connect" feature to precisely put pins, etc into the right pin holes, but that didn't seem to work for connecting pieces at their "natural" angle. I did some trial and error by putting in values that seem to make things connect, but of course that's nowhere as accurate as their real-life angles.

For context, this is a suspension setup I'm working on. The suspension is a simple sprung one like 42075's rear suspension, but the left and right wheels are suspended independently. This means there are 3 unknown angles - the point at which the shock absorber connects to the chassis, where the shock absorber connects to the suspended section, and where the suspended section is connected to the chassis. If necessary, I can also provide a screenshot of my work so far.

I've always been intimidated by digital building, so I've never really made any efforts to learn it. But this time I'm finally making it a goal to build an entire MOC digitally and make instructions for it, so any help from stud.io (or other digital building software) experts will be greatly appreciated. 

[Jundis]

Do you use the "Hinge" feature? Just connect the piece to a pin and rotate it... you can send me a message if you need help :-)

[Andman]

@JLiu15, could you show the suspension? Are you missing a feature which let's you connect a part 1 on point b while it this part is connected to part 2 on point a and thus is following part 1?

[CrankyCraig]

You might reasonably expect there to be some sort of connection tool to attach 2 or more complex angles at specified points such as that of suspension, but unfortunately (and to my surprise) there isn't. I asked the same question a while back of the members here, in the software section and also a couple of professionals, and received the same answer from each - there's no way to do it beyond trial/error. 

Sorry. Not the answer you wanted, I know.

[Captainowie]

If you don't mind a learning curve that's a little steeper, I'd recommend LDCad as an alternative editor. It has a triangle solver so that you can set precisely the angles you need for each part, and relative grids, so that once you have one part on the correct angle, you can set the relative grid to that angle, so that all parts connected to your sloping part are positioned correctly.

[astyanax]

Agreed 100% with @Captainowie -- switch to LDCad (and LPub3D for subsequently generating instructions) while you still can.

@JLiu15 Please note that there's a subforum dedicated to this kind of digital buidling questions. Probably an admin will soon move this thread...

https://www.eurobricks.com/forum/index.php?/forums/forum/128-lego-digital-designer-and-other-digital-tools/

[JLiu15]

On 12/2/2020 at 7:43 PM, CrankyCraig said:

You might reasonably expect there to be some sort of connection tool to attach 2 or more complex angles at specified points such as that of suspension, but unfortunately (and to my surprise) there isn't.

Yeah, unfortunately it looks like the only way to connect pieces at complex angles is trial and error. However, I was able to build my MOC in there just fine.

On 12/3/2020 at 4:52 AM, astyanax said:

Agreed 100% with @Captainowie -- switch to LDCad (and LPub3D for subsequently generating instructions) while you still can.

Good to know - I'll probably try it out sometime and see how it works for me.

[BusterHaus]

On 12/3/2020 at 2:53 AM, Captainowie said:

If you don't mind a learning curve that's a little steeper, I'd recommend LDCad as an alternative editor. It has a triangle solver so that you can set precisely the angles you need for each part

The only limitation is the number of digits calculated by the LDCad. It's not really an issue for simple builds, but the miniscule rounding errors start to add up if you have many angles. 

To be honest I don't remember if this issue is specific to LDCad, it may have to do with the number of digits used by ldraw to define rotated parts. 

[Philo]

16 hours ago, BusterHaus said:

The only limitation is the number of digits calculated by the LDCad.

LDCad information tool gives 5 decimal places, which should be more than enough for most usages. The limiting factor actually seems to be the number of digits kept when you save (3 dp), but that could improve in the future.

[roland]

5 hours ago, Philo said:

LDCad information tool gives 5 decimal places, which should be more than enough for most usages. The limiting factor actually seems to be the number of digits kept when you save (3 dp), but that could improve in the future.

LDCad internals uses double precision everywhere. But because the LDraw format is human friendly you will loose information due to rounding once you save and reload a model.

In very complex models this might become very noticeable after an couple of save/load sequences.

A possible solution might be to increase the number of digits LDCad uses during saving.

For this edit the main.cfg file while LDCad is closed and change

modelFileDecCnt=3

into eg

modelFileDecCnt=6

Some additional options might be available in 1.7, but the increased number of digits should at least help right now given you set it before you start a complicated model.