Best Practices to 3D Print and Paint STL files from Revit

Bambu Lab Software
1

Hello everyone,

At my office we got a Bambu 3D printer and are trying to use it to create models of our projects and the painting feature in Bambu looks to be very promising for marking out roads on topographic modules and material differences in buildings but I find the paint tool seems to only want to paint the edges of walls and floors making it virtually impossible to paint anywhere in the middle.

Is anyone else exporting STL models out of Revit and running into this issue only being able to paint the edges of elements?

Thanks for any help, and I will be sure to post more info if I find any solutions to this or adjacent problems.

2

Are you able to share a model so we can see the geometry?

3

@Eponymous See below a link to the STL example Topography I just exported out of Revit. Let me know if the link does not work, it is a shame that the form does not allow us to upload small STL files.

Thanks for the help!

4

This model is not manifold (it is not solid). Was it designed for 3d printing or just CGI rendering?

There might a 3d modelling tool that can repair it, or you might be able to export it in a different way.

5

Are you trying to paint just individual colours where you need them?
OR are you trying to paint based on things like elevation data or how much something sticks out of the model?
Asking as there would be quite big differences in the approach…

6

I am trying to paint paint individual colors where i need them. Such as paths, roads etc.

Thanks!

7

@Eponymous Ok, that is weird because Bambu seems to print the topography perfecrly fine, i just cant paint it easily.

8

Doing colours like this from an STL file is VERY hard…
One option would be to use a modelling software to cut the model into two or more parts - one per colour.
STL files though are about the worst to use for this…

You face several problems here, apart from the file format itself…
A single model that has to split into multiple models.
Doing these cuts without changing the geometry of the file.
Being able to export those now individual files without further losses or defects.
Not that it would be much better using OBJ files or such.
On the screen we can use a simple model and do the rest using textures.
But AFIK there is nothing really to use textures to be applied to split models or assign surface layers of different colours.

Does not happen often by on this one I am right now out of ideas :frowning_face:
Hopefully someone else did such things already or knows some easy workarounds…

9

What?

what_kirk.thumb.gif.70b2b23aa23a2941e8842dad5086b144

A model doesn’t have to be manifold but if it isn’t, support needs to be turned on. Perhaps the top surface doesn’t have enough layers to allow detailed painting. But that’s just a guess.

10

Non-manifold means there are structural errors that prevent the object existing in real life.

Some slicers can sometimes fix this, and it will often print ok. Sometimes. They’re a lot better today than they were in the past.

Essentially the result of working with a non-manifold object is “undefined” until you try it and see if it works.

11

Rather than colouring the models in Bambu Studio you might want to consider doing the colouring in Blender, then using this very interesting feature being worked on to allow coloured models to be directly imported into BS

See

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12

The meaning of Manifold has variations. You are referring to a mathematical manifold. In 3D printing, we must consider geometric manifold. It typically refers to an object with “water tightness”. And non-manifold objects do exist in real life. Consider a Christmas Ornament. Remove the hanger and you have a globe/sphere with a hole in it.

13

Copilot just gave me some more examples of objects that are considered non-manifold but do exist in real life.

  1. Cross (X):
  1. Cone:
  1. Sphere with a Hair:
  1. Thin-Walled Objects:
14

I have used manifold in the 3d print sense. A non-manifold object cannot exist in real life (of 3d print). In your example of something “non-watertight”, it has zero width gaps between 2 separate surfaces. In real life these are a single surface.

The slicer does its best to approximate what you wanted, and sometimes gets it right. I would not be surprised if the behaviour was actually unspecified.

I’m not sure why copilot has jumped down some mathematical hole. None of these AI systems are particularly able to understand context.

15

It’s not weird if you accept that the model has errors, and you therefore break the contract between you and your slicer (which is that it will work properly if given a correct model)

I think a good analogy is that you tell a company to sort out red and blue marbles and then package them for shipping by colour, and then you thow in a pink marble. There are many workers in that building, in different stages of the operation, all of which have only been instructed how to deal with red or blue marbles. Perhaps they treat red as similar to pink, or perhaps they pull the alarm, or perhaps they throw away the pink one and carry on? Each one will make their own decision, because there is no guidance from HQ in the form of a specification or procedure for pink.

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@Ukdavewood Thanks! this might be the best course especially if I will likely need to bring the models into blender anyway to fix the topography Manifolding issues. Do you (or anyone else) know what file format would be most recommended? I instantly jumped to STL since that is what I always used 5 or so years ago when I was hobby printing but Revit is also able to export in .OBJ. Is there any benefit to switch over to .obj?

17

I would certainly try OBJ first - especially if the source models already have some colouring in them - as Blender should import them already coloured for you.

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