DXF and Surface Entities

[TheVelourFog]

Hello all,

 

I have been scouring the net looking for a way to read in the DXF data for a surface entity in AutoCAD2012. There's plenty on reading in simple objects (e.g. 3DFace, Points, etc.) but nothing on surfaces. The data itself is also not as intuitive as I would have hoped. The DXF reference PDF from AutoDesk shows 7 possible unique entries and the data I need is most likely stored in the proprietary data. So, in short I know where it is but how can I read it? The DXF format is fairly new to me so any help/guidance would be fantastic.

[fuccaro]

Read about (old style) polylines.

[navasender]

hello,

I have the same problem. I would like to know the structure of the SURFACE entity in AutoCad 2012.

[BIGAL]

First step why ? what are you actually trying to do, you can get at the surfaces info from within Autocad. If your trying to develop something at a high level Autodesk provides developer toolkits.

[navasender]

I'm trying to generate a DXF file from an external program, because I want to plot a 3D surface. I have looked with a text editor the lines that define a PLANESURFACE in a DXF file, but there is a lot of information impossible to understand, completely differente from the rest of normal entities. So, I need to know is there is an easy way (or not so strange way) to do that. Thank you.

[BIGAL]

Ok what about 3dfaces these can make a defacto surface and are listed in dxf code pretty sure 4 3d points.

 

Second forget dxf go straight to DWG there are tool kits out there this is how all the other Autocad clones came into existence.

[navasender]

Yes, I have worked with 3DFACES but this is only valid for faces of 3 or 4 vertex. I wanted to improve the generation of surfaces with PLANESURFACE for any number of vertex. Anyway, What are the tool kits that you tell me? Is it possible to make an automatic draw from outside AutoCad generating a DWG file? For example, what I am doing now is to introduce the data of the plot in an Excel sheet (dimensions of my figure, styles, layer etc) and automaticaly with Visual Basic Application I make the DXF file. Can I do that but making a DWG file? Thank you

[BIGAL]

You can definately generate dwg's outside of Autocad you will need to serach the NET most software companies of a reasonable size have got hold of this kit.

 

I dont understand the number of faces using 3dfaces can be literally millions.

 

If your writing a dxf and then you are loading into Autocad why not cut the middle step out all together and just read the data from excell directly from Autocad and draw Autocad entities. You can use VBA but I would go to .net