Building clean printable models in C4D

[qmaker 29]

Hi,

I have been building models in c4d lately and have attempted to create several models with simple parimetrics and extruded text. When I make everything editable and export my stl, I find that overlapping parametrics and caps of text etc... seem to cause geometry problems. Either not welding at the seams or not combining properly. If I send them over to zbrush I can usually mess with it and make a usable solid mesh. I do use Netfabb to repair models. However I wonder if changing my modeling process would help.

Example. If I put two tubes together, is it best to Union them together with a boolean, or simply make them editable and then connect objects and delete.

Thanks,

Q

 

[scooby 0]

Hi,

I haven't used boolean software in a few years, I primarily use solidworks now, so I may not be too helpful but I remember running into problems with infill if the boolean union had scrambled geometry due to crazy curves. I also just started using meshmaker for creating my own custom support for my prints, and I noticed that the program is used primarily for making boolean meshes. its free you should check it out if the problem persists. Sorry I'm not more helpful, figured I should toss out a few ideas.

 

[valcrow 144]

Yes, ideally for a cleanly printable mesh you need to boolean. Cura attempt to slice it properly anyways if you have Fix horrible A on. (which is on by default). But better and more predictable if you provide a proper mesh for slicing.

I can't remember if it was C4D or another program that did this, but extruding text doesn't create a proper capped surface that welds onto the sides. If there are holes and non-matching topology it's going to give you problems.

Ideally for printing you need an entirely enclosed volume with no interpenetration and double faces.

 

[qmaker 29]

Yes definitely, if I make extruded text I notice that it doesn't weld the caps. I have had some success optimizing the mesh after making it editable, but many times it just fills in the centers of more complex letters. C4D is my main modeling program unless I am creating something organic, then I use zbrush. Either I need to figure out how to make better topology in C4D or use something else for these simpler builds. Thanks for the help.

 

[valcrow 144]

For weird shapes like O's and P's where there is a counterform shape (I assume that's what's being filled in during a cap operation). You just need to bridge (or create a custom poly) from the inner counterform to the outer edge. This will separate the two borders so they aren't two separate continuous shapes. so an O becomes a U and this will cap a border properly.

Hope that makes sense. It certainly doesn't sound like it does.

 

[francfalco 37]

I too use c4d for all my modelling, and the boolean can cause issues.

But i also run everything via Netfabb and once its been 'fixed' - i never have problems.

I also wouldn't make your geometry 'editable' before exporting - just leave it parametric and export. Fix with netfabb and you should be okay? i know that isn't the correct optimised way to model for 3d printing, but i does work for me.

I am though intrigued why you're having problems. I'd be happy to look at your c4d file to see if i can see the problem areas if you like?.

Let me know

cheers

 

[qmaker 29]

Thanks guys, for now I have it working. I will give exporting my .stl files without making my geometry editable and see how that works. It seems like basically the caps on text don't weld properly to the extruded sides and then netfabb tries to weld it back together and closes over Os Ps etc... I tried changing my cap subdivision level etc.. and had better luck. Does 3d printing prefer to have few and simple polygons or more? If I don't figure it out I may take you up on having a look at my model to see if there is something I am missing or doing wrong.

Thanks,

Q

 

[valcrow 144]

You probably have to do a manual cap. I'm not sure about blender, but in Max you can select the border and do a cap operation on the text face. If it is a closed shape like an o or p, you need to bridge one polygon first and then cap it.

As for polycount, somewhere in the middle is good. If you're too high, it'll make lots of tiny lines which are bad for surface quality sometimes. If it's not dense enough you will see polygonal facets. It is best to turn OFF smoothing groups in your view to get a good idea of what your object will look like since 3d printing doesn't take into account smoothing groups only raw triangle data.

It sounds like you are experiencing welding issues rather than a polycount one though... polycount doesn't really play into the print quality unless it's at either extremes.