Hi there.
I have an stl file that I want to modify using CorelCad. Here are the steps I used:
1) using a different 3D program, I exported the stl file as a dxf file
2) Using CorelCad, I opened the dxf file. It looks perfect.
This is where I am stuck. CorelCad will not allow me to simply export that imported file as an stl file. There message I get is, no entity found. I get this message when I select the objects just imported and try to export them. (File>export>export STL, command line states: Specify entities>> I then select the entities and then the command line states 0 found)
Does anybody know what steps I should follow in order to export the imported dxf as an stl file?
I figure I need to make it a solid first but I can't figure out how to do that either.
Any help would be appreciated.
thanks...
Hi Paulus,
STL files are surface files, not 3D files. They are significantly different to how CorelCAD stores information and while it's theoretically possible to create a complicated model from a STL file into a 3D file, a direct conversion will only give a surface mesh. You can look up more about them on Wikipedia -
As a result, a conversion isn't going to create a solid file, but a file that contains mesh faces. These aren't solid files but 2-dimensional files. Theoretically you could go from this to a 3D solid, but I don't know of any CAD program that does this automatically.
This isn't just a CorelCAD limitation - You will also find that many CAD users have the same question, regardless of which package they use.
Put simply, CAD is for high-precision mathematical models that can be created. There is a huge loss of information in the process of going from one to the other, and trying to use a CAD application to edit STL files is like trying to take the flour out of a cake that's already been baked so you can turn it into bread.
The most effective way of using CorelCAD with STL files is probably to rebuild them from scratch. This is because you can't undo a process which involves loss of the original data. Rebuilding the file from scratch reconstructs the original data.
It's not the only solution however.
You can always try applications such as "meshtosolid" which tout themselves as being suited to such applications as you've mentioned - I thought I'd see how effective it is and ordered a trial license, but haven't been able to evaluate it - So I have no idea if it will meet your requirements.
You could probably write an application to do much the same too, which on a simple level could be as simple as creating prismatic faces from each tesselation and then extending one direction in a planar direction for at least the dimension of the object, unioning all the objects then co-placing all six objects and keeping only space common to all six. This isn't perfect as it will lose internal detail, but would be functional. Another approach would be to slice the object at the desired resolution into many planar shapes and loft them together.
None of these solutions is really ideal however. Generally the best solution is still to recreate the object under CAD.
Please let me know how you go with this -
Thanks
David.
Thanks for the reply. I kind of thought that but was hoping that somebody had come up with something, a method. But that's OK since you're probably right. The best thing is to start it from scratch within CorelCad.
thanks again...