model for 3d print

[Dune]

Has anyone of you ever modeled something to be printed in 3D? I received a query to make a realistic 1min. animation of a castle and have it so the castle (no trees, ha) can be 3D printed. I normally build buildings with open ends and loose parts, so this seems quite different after seeing some tuts.

[j meyer]

Haven't printed anything yet,but have modeled some things ready to print and
know about some basics.
What are your questions?

[Dune]

I've learned a little in the meantime, like not having open ends (so watertight parts), or very thin areas, the need for triangles, lots of polys to smooth edges, minimize volume. Possibility to have intersecting parts, and use image maps to texture. But I guess things like half-open shutters are not easy, unless completely separated from the wall and to be glued on later. No need for window glass to have a reflective shader, but I guess just made a very dark color.
So, no real questions atm. but any important pitfalls I may fall into while modelling, I'd very much appreciate to hear.

[Hannes]

I once modeled a piece of chainmail (I think I already posted this some time ago somewhere here...). See attached photo.
It's really tough to get your model "waterproof". My chainmail was quite simple, but until I got it right, I had to tweak a lot of things. Intersecting objects are possible as you can see, but intersecting polys inside the object are not. If you have a quite detailed model with maybe some issues that don't matter for rendering, it can be very hard to clean up this object until it's really printable.
And it's a bit tricky to get the scale right. Some 3D print services have the possiblility to adjust the scale while ordering.

[Dune]

Thanks Hannes. I just have to build it up very carefully, and keep these things in mind constantly. If these guys still want their castle....

[j meyer]

Yep,watertight (closed) surfaces and a for sheet like things enough dimension
(thickness) are the most important points.
Hollow out big parts.
Exaggerating some details can be necessary so they won't get lost in printing
or production,in case it's used as a prototype for casting.
Half open shutters should indeed be separate parts,might save printing space
as well.Other protrusions like chimneys or so maybe too.
As for the size I don't know what units Lightwave has to offer,but you can always
get yourself a reference object of known dimensions.Metric system is preferred
as far as I know.
Do you know if it's meant to be casted and which company will print it?

[Dune]

In LW you can work in meters or centimeters, but I have no idea yet if and how big and detailed they want their castle. Nor where they want to have it printed (not cast I expect). I hope they'll give me the job though, nice challenge. But it might just be some vague idea by someone having no clue about time and cost involved.