Manifold
Posted by Replace
Hi all,
As a newbie, I sometimes don't understand the vocabulary.
As for now, on some objects that I try to slice, I get the error that the object is not manifold on some spots.
What does that mean exactly?
These are objects I did not design myself, but which I got from someone else.
So please can someone explain theh manifold term and what to do if this is a problem for slicing?
Rgrds. Thomas
www.3daybreaker.blogspot.com
Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)
As a newbie, I sometimes don't understand the vocabulary.
As for now, on some objects that I try to slice, I get the error that the object is not manifold on some spots.
What does that mean exactly?
These are objects I did not design myself, but which I got from someone else.
So please can someone explain theh manifold term and what to do if this is a problem for slicing?
Rgrds. Thomas
www.3daybreaker.blogspot.com
Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)
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Re: Manifold May 05, 2012 06:29PM |
Registered: 14 years ago Posts: 2,947 |
Manifolded means air / water tight. So if you are getting a warning the part is not manifolded it means you have a hole in the model. Most often is just a gap where two vertices don't touch correctly and can be fixed with ease using Netfabb basic or cloud.netfabb.com
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Re: Manifold May 05, 2012 08:43PM |
Admin Registered: 18 years ago Posts: 7,883 |
It is not that the object is watertight, you can have a model of a sieve that is manifold. It is that the triangle mesh representing the surface does not have bits missing, or extra triangles or many other defects that mean it describes something that cannot exist physically.
For example consider a model of a sphere made from triangles, then remove one triangle. What you then have is no longer a solid sphere with a defined inside and outside. It is more like an infinitely thin shell of a sphere with a hole in it, something that cannot exist in reality, only mathematically.
[www.hydraraptor.blogspot.com]
For example consider a model of a sphere made from triangles, then remove one triangle. What you then have is no longer a solid sphere with a defined inside and outside. It is more like an infinitely thin shell of a sphere with a hole in it, something that cannot exist in reality, only mathematically.
[www.hydraraptor.blogspot.com]
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Re: Manifold May 06, 2012 01:20AM |
Registered: 15 years ago Posts: 862 |
Ahh, i get the picture.
So, if I can not diagnose the object for the " holes" , I might get lucky and the object might print after al correct?
For as I understand, holes are not always a prolem for the printer, as long as overhangs and bridges are within some limits?
Thomas
www.3daybreaker.blogspot.com
Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)
So, if I can not diagnose the object for the " holes" , I might get lucky and the object might print after al correct?
For as I understand, holes are not always a prolem for the printer, as long as overhangs and bridges are within some limits?
Thomas
www.3daybreaker.blogspot.com
Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)
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Re: Manifold May 06, 2012 05:08AM |
Admin Registered: 18 years ago Posts: 7,883 |
No this isn't like a hole in a an object, this is a group of triangles that don't go together to model a solid. An STL file is just a list of triangles. It is very easy to make a list of triangles that don''t all mesh together to represent a solid.
If you consider the sphere example above: a proper model of ball with a hole in it would have an outer surface and an inner surface and a short cylinder connecting them. Each triangle in the model would have one face on the outside of the surface of the object. With one triangle missing both surfaces of all the other triangles are reachable from the outside of the object.
Whether it prints or not depends on how the slicer interprets it, rather than the ability of the printer to print overhangs. It could interpret it as an infinitely thin sphere and print nothing. It might interpret it as a solid sphere and ignore the missing triangle. It might change its mind part way through and have some layer missing so the top of the sphere gets printed in mid air.
[www.hydraraptor.blogspot.com]
If you consider the sphere example above: a proper model of ball with a hole in it would have an outer surface and an inner surface and a short cylinder connecting them. Each triangle in the model would have one face on the outside of the surface of the object. With one triangle missing both surfaces of all the other triangles are reachable from the outside of the object.
Whether it prints or not depends on how the slicer interprets it, rather than the ability of the printer to print overhangs. It could interpret it as an infinitely thin sphere and print nothing. It might interpret it as a solid sphere and ignore the missing triangle. It might change its mind part way through and have some layer missing so the top of the sphere gets printed in mid air.
[www.hydraraptor.blogspot.com]
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