WATERPROOF polygon objects in STL

[Stray]

What They are refferring to is a mocel that is a solid. Say for instance if you made a lofted spline between 2 open spline objects it would have heighth and depthbit no width. Conceptually the width woould be zero. So if you have a surface ( say in another case) a car where the body is a lofted or swept like "surface model" the machine couldnt print it out because of that lack of width of the sweept shape.

Classically "solid" models are continous 3d shapes that are closed. Say if you used a standard Boolean object to take a sphere out of a cube. That type of modle would be printable. But if that cube had an opening without the faces that comprised the hull of the spehere taken out of it. It would suffer fomr the same error.

The expression "waterproof" means that if your model were filled with water it would not leak out of it. Visualize a milk jug with its cap on. It is waterproof becasue it is one contiguous surface that has depth height h and volume. If you took the cap off then it woulnt be if the surfaces had no thickness to them.

I hope I made sense.

-D

[mogh]

I made several Models for Rapid Prototyping out off cinema.
No problem there.

Just read the last comlum from stray. (the above is a bit confusing stray *g*)
And for testing i Use a hypernurbs an look if the surface isn't broken -> seamless ...

If its only small holes which can be there from export and so on the companies close them normaly. But if you are a student and get a fair prize they wont, or there are real many holes or they dont know how you would like to have them closed (milk bottle cap or thikness for example -> thats your task).

cya

[jimlock]

for stray:

Thanks for your reply. i guess it's my fault i didn't explain. i knew all the above you mentioned. my car has a surface that is 5mm fat, meaning its not a thickless surface.it is a solid.

Problem is that the man from the company said there are still problems..holes i guess.
He did'nt say much. Mogh couldn't be more right. I AM a student and i AM getting a fair price. So i guess he didn't go into much trouble to find out where the problem is..

..as for testing it with a hyper nurbs, its all hypernurbs, so i guess i would have seen a hole if there was one..

One detail i left out is that i cut my body into pieces using boole.
after i made the whole boole editable i connected all poly objects together into one and then i optimized my points so as to connect all polys together..
To make sure it worked, i then selected a few polys right on the cuts ( there where before the connect command u'd find bordering polys that belonged to different poly objects) and pulled them here and there to see whether they are connected with their bordering polys or not..

i hope i made sence here...

Mogh since you 've worked with rapid prototyping before, is there any other advice u can give me..??
I mean is there a way ..some sort of command in cinema that can check a poly object and tell you whether it is a solid or not??
..some sort of command that can check to find edges that belong to only one polygon?
that can check for polys that don't border with other polys??

i hope i made some sence even more this time...

thanks again guys..

[mogh]

I don't know of a comand so i use deformers and the hypenurbs to visually check the mesh (after i molten it down to one poly - not bevore!)
Perhaps if you put in a explosion deformer and set the min polys above the sum of your car polys it shouldn'nt blast in pieces. This works even with half connected Polys (i tested right ahead).

there is no certain way to check - you have to workaround.
One thing that could help adittionaly is the
Structure Info Window and the Selection Info Window ...

but start with throwing the car in a hypernurbs after you connected all things to a simple poly Object.

by the way these Rapid Prototyping Tools are sometimes sloppy programed (not in the way we are used to cinema) and just say "NO" instead of telling where the problem is. There are some external apps which check the Meshes (don't know the names).
Some Apps even don't want intersecting polys so perhaps check for that too.

cya

[alawrence]

Hi

I often have to translate my C4d models for stl. Sometimes it can be easy, othertimes a nightmare. I take my model into formz which is a solid modeler and can tell me if the shape is well formed and a solid or surface, something which is missing in C4d.

Unfortunately I have not found a 100% reliable technique yet. I often go backwards and forwards between apps to see if it is "waterproof". Always double check points on the mirror axis, remove all symmetry tags and oprimise, optimise and optimise. Increase the point welding setting as this can sometimes help.

I hope you find a solution as I am interested in solving these problems too.

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