simtk.org

Hello,
I need to make some changes on my model after creating it in simvascular.
I opened the poly data "vtp" file in paraview and saved it as a STL but solidworks can't read the file since there are too many faces.
I was wondering if there is any other solution.

Thank you!

Hi Atefeh,

The PolyData model is very different than the model type used in SolidWorks or other CAD softwares. SolidWorks uses non-uniform rational b-spline surfaces (NURBS), which are spline-based models.

SimVascular supports another model type, OpenCASCADE, that is in a NURBS format. When you go to create the model in SimVascular, instead of using PolyData, use the drop down menu for the model type and select OpenCASCADE. This can be saved as a .step or a .iges file, which can more easily be imported into SolidWorks.

Thanks!

SimVascular Development Team

Hi Adam,

I need to make some changes on my models. I have created a model using "Open Cascade".
however when I use "blend" with any radius, the software crashes. And also none of smooth or decimal local options are available.
I had run my simulations on the blended models using poly data and I need to have the model used "openCascade" to be similar to the the "poly data" made models as much as possible.
I was wondering if you may have any suggestion.

Thank you,
Ati

Hi Ati,

Are you importing your model as a STEP or IGES file? If you are then can you post the file here so I can try to reproduce the problems you are having?

Cheers,
Dave

Hi David,

I tried IGES.
My problem is before exporting the file as a STEP or IGES format, how I may recreate the geometry using CASCADE similar to the one using POLYDATA.
I tried to attach the models using both CASCADE and POLYDATA (.vtp and .brep) but they seem too large to be attached .
I tried to send the exported iges or STL and I get the error invalid file extension.

Thank you very much,
Ati

Hi Ati,

I've created a GitHub Issue for this problem, see https://github.com/SimVascular/SimVascular/issues/398.

You should be able to upload the model there. You will need to have a GitHub account to do this.

Cheers,
Dave

Hi David,

I posted the models made using both CASCAD and POLYDATA .
The are in "vtp, brep, iges, and step" formats.

Thank you very much,
Ati

Hi David,

I also noticed when importing the model into Solidworks, dimensions were smaller (about 1/10) than expected.
Since I created the model straight from the MRI images, did I still need to rescale the model?
Since my simulation results were accurate, I was wondering how this scale mismatch may come from.

Thank you and I look forward to your answer,
Ati

Hi Ati,

I think there are a couple of things that may have happened. One is that there was a bug in SimVascular that caused a scaling problem when saving image data in VTK .vti format. When reading the image data back in the scale was wrong. The latest release of SimVascular fixes this.

Another issue might be that SimVascular does not assume any units so you might need to scale your image data.

Cheers,
Dave