I have to create an part of a model. Outside on the wall details should be applied.
However, these always hang in the air, because the wall does not follow the given curve, but runs as a straight line (secant).
How can I avoid this?.

Different methods can be possible depending of your precision wished

Extrude a volume toward you wall / Intesect ...Fillet etc

Project curves to your wall ...extrude...Fillet etc... (best)

"Flow" a volume to your wall

Draw a curve on your wall ...extrude...Fillet etc...

etc...

here the Flow method ( Transform / Flow)

Hi ibba, yes you'll want to make the details to come from the main large surface like for example trimming the large piece. There are some examples here:

http://moi3d.com/forum/index.php?webtag=MOI&msg=3024.4
http://moi3d.com/forum/index.php?webtag=MOI&msg=4010.4
http://moi3d.com/forum/index.php?webtag=MOI&msg=3318.1
http://moi3d.com/forum/index.php?webtag=MOI&msg=4791.13
http://moi3d.com/forum/index.php?webtag=MOI&msg=3859.2

However, when I examine your piece closely it appears that it is in the shape you want already, the detail is actually already following the same curvature as the main wall.

Maybe it's an issue where you need to increase the density of your polygon mesh export. The slider bar in the mesh options dialog controls the angle parameter, that dices up polygons based on a maximum allowed angle between vertex normals.

However, shapes that are only very slightly curved will not be subdivided very much by that parameter alone, to bring out details on shallowly curved areas you'll also need to use the "Divide larger than" parameter in addition to angle. You put in a distance value in "Divide larger than" and it will then dice up your model more finely like this:



Does that help?

- Michael

Seems I have not understood the problem asked :)

Hi Michael,
The curved wall is part of a tramcar model body. Normally, I draw the floor lines in distance of wall thickness, connect both side ends with lines and extrude to the desired height. Alternatively, I draw the vertically profile of the wall and drag it along the floor plan (sweep).
Also, I have already cut out such a curved part from a block and all other methods given by Moi.
In all cases, the course of the inner and outer wall surface is not identical to the given curves. This has nothing to do with a mesh because the error is already visible in the 3dm file long before creation of STL file.
When you zoom in on the view from above, you can see a gray area next to the given lines (red and green) that indicates the "wrong" course of the wall. This wrong course will be shown also in STL file, that's clear.

Bodo-Lutzt

Hi Bodo-Lutzt,

re:
> This has nothing to do with a mesh because the error is already visible in the 3dm file
> long before creation of STL file.

There is also a mesh being used implicitly for the display of shaded surfaces in the viewports. The error here is just a display artifact due to a low number of triangles being generated for the display mesh.

Curves and edges are drawn in a different way which has higher accuracy, so basically when you see something like you show here where the edges look good when zoomed in but the shaded stuff is a little chunky that's usually just a display artifact due to low display mesh density and your actual model is fine.

When you have a shape that is curved only very slightly and shallowly like this, you need to use the "Divide larger than" setting when exporting to a mesh format for the subtle curved shape to come through very well.


> When you zoom in on the view from above, you can see a gray area next to the given
> lines (red and green) that indicates the "wrong" course of the wall. This wrong course will
> be shown also in STL file, that's clear.

Here's what an STL export using your file looks like when the "Divide larger than" parameter is also used to make sure things are diced up enough, that is what you should use to solve this:





- Michael