Trimesh from imported trimmed IGES surfaces

[Mr. Stefan CFD 0]

Hello,

 

I am trying to build a trimesh for the JBC hull by importing IGES file format surfaces.

 

The trimmed surfaces are rendered back as if they were never trimmed.

 

One solution I found is to import in STEP format, resulting a BrepPart. However, the adaptive tessellation feature can't be controlled as in the case of a NurbsSurface.

 

How this issue can be resolved?

 

Many thanks,

Stefan

[Mr. Carsten Fuetterer 9]

Hi Stefan,

 

you can change the tesselation in the display option directly on the Brep Part. When you put this Brep into a triMesh the tesselation is used directly from the brep.

 

best regards

 

Carsten

[Mr. Stefan CFD 0]

Hi Stefan,

 

you can change the tesselation in the display option directly on the Brep Part. When you put this Brep into a triMesh the tesselation is used directly from the brep.

 

best regards

 

Carsten

 

Yes indeed, thank you!

 

Though, I wonder if there is another way, because I've seen a PDF, "From IGES to STL", that's giving advices to mesh Duisburg Test Case (DTC) hull.

 

I know for sure that this hull's having trimmed surfaces at least in the aft body part, precisely at propeller shaft intersecting the hull.

 

Thank you!

 

 

[Mr. Carsten Fuetterer 9]

Hi Stefan,

 

now I don't get your point. You can use any brep to convert to stl, no matte if it is trimmed or not. I am not seeing your problem.

 

Carsten

[Mr. Iorga Stefan 1]

Hi Stefan,

 

now I don't get your point. You can use any brep to convert to stl, no matte if it is trimmed or not. I am not seeing your problem.

 

Carsten

 

I was thinking of blade analysis feature that requires as an input NURBS/BSpline surfaces. Suppose you import a trimmed blade face.

 

But, this is another topic.

 

Thank you

 

 

[Mr. Carsten Fuetterer 9]

Ah ok, no we can not create a "new" Nurbs surface from a trimmed one.

 

regards

Carsten

[Mr. Stefan CFD 0]

Ah ok, no we can not create a "new" Nurbs surface from a trimmed one.

 

regards

Carsten

 

I didn't tried, but maybe a subSuface of it? Or I have to build again in Rhino3D, for example, the actual surface?

 

Thank you!

[Mr. Carsten Fuetterer 9]

Hi Stefan,

 

in case of a propeller blade I don't know why to use trimmed surfaces. A subsurface from a brep will not work. So the only case, where I can think of problems is the blade analysis, but here trimmed surface can be avoided pretty easy I guess.

 

best regards

 

Carsten

[Mr. Iorga Stefan 1]

Hi Stefan,

 

in case of a propeller blade I don't know why to use trimmed surfaces. A subsurface from a brep will not work. So the only case, where I can think of problems is the blade analysis, but here trimmed surface can be avoided pretty easy I guess.

 

best regards

 

Carsten

 

Hi Carsten,

 

Look at the green colored blade face how it's over-lapping with the grey colored one.

The yellow curve is the edge of the blades if they were untrimmed.

 

In the second image the control points of the nurbs surface is activated.

 

I was thinking to import in CAESES the boundary curves as well as two nurbs surfaces and trim them back. Otherwise, the BladeAnalysis feature is giving erroneous results.

 

Sure, I can rebuild the surfaces, but it's taking far too long.

 

Best regards,

Stefan

 

PS: This is off-topic already, can you modify accordingly the title? 

 

Later edit:

The only way I suppose this will work, is by importing as BrepsParts and Extract Surfaces and Boundary Curves, however, the results are not as expected:

blade-face.fdbc

[Mr. Iorga Stefan 1]

Mr Carsten,

 

What do you meant by saying that trimmed surfaces could be fairly easy to avoid?

 

Thank you!

[Jörg 29]

Hi Stefan,

 

Maybe you can try to use image surfaces: take the larger surface of your blade, and change the U or V domain to make it smaller. If there is no overlapping left, the blade analysis should work again.

 

Cheers

Joerg