Hi, I need to model a complex topography in phoenics. I have an autocad file including 3d polylines that I need to transform into a single solid in order to export it as STL object.

What is the best way to do it ? Shall I better try to make a 3dmesh and to export it as a DXF? Someone told me that Phoenics was not so reliable with DXF geometry...

Thanks for your help!! Fred

I already tried to simulate a complex topography once, but I had to make several solids for each level of the terrain and after that I put all then together to form the single object and export it as a STL file. The problem is that you have the terrain represented by several steps instead of a smooth surface, but I don't realize another way to do it using solids.

Tell me if you manage to do it. Good luck!

HI Im running some cases of scour at bridge piers, until now, generating the geometry has been the main problem, the best way i have found is editing 3d shapes, moving the original nodes, you can do this using infini-d or 3d studio, but i dont know why, the best way for exporting to phoenics those geometries is doing it from 3d studio generated 3d solids in the stl format, it has been the only way that phoenics imports the geometry.

hi Fred, I had earlier trid to import DXF files into PHOENICS but was not successful but as far as STL is concerned, theres jst no problem is there no option in AutoCAD to group 3d objects? Arnie

Hi,

thanks a lot for your help.

I do confirm that exporting STL object is easier with 3d studio than Autocad. It appears that Autocad is not so usefull with 3d... the soft 3d studio allow us to make "smooth" surface from 3d polylines, then it's easy to extrude the surface in the z direction in order to export the solid as a STL object (ASCII format). Moreover, when making the surface 3d studio allow the optimization of the total number of triangles to get more or less precision. After importation in phoenics, The VR editor show all the complexity of the topography. I did not find any solutions with DXF... Fred

Ive not used autocad, but I have found the AC3D package as supplied with PHOENICS to be very useful. One can import many objects in the various formats and export as a PHOENICS dat.

The PHOENICS prefered import format is STL and the main problem I have found when importing is that the CAD object may have been made incorrectly, for example perhaps some facets have their normal pointing inwards instead of outwards, or holes exixting in the object. But saying that they can usually be fixed quite easily. PHOENICS can definetly import STL very succesfully.

If after importing your CAD object into PHOENICS you find that it is represented by steps instead of a smooth surface then something has gone wrong which can be corrected, either there is something wrong with the CAD object or the PHOENICS code is not being set up right. I have found that I get my best results from combining may CAD objects into a single STL and importing into phoenics. Of course I keep them seperate if I'm doding stuff like conj heat transfer and they are different participating materials.

Just to add some points here.

I had worked on importing some geometries into PHOENICS from AutoCAD. I found that I could only do it through stl files. I also found that when creating 3D objects in AuotCAD that I had to be careful with the FACETRATIO (I think that is the autoCAD Command, anyways it refers to the Facet Ratio) if I was subsequently importing the objects into the cylindrical-poler coordinate system.