How to Adjust Geometry Facets in SimSolid Cloud

SimSolid Desktop is a transformative tool when it comes to reducing preprocessing, specifically its meshless technology and its automatic contact and fastener creation. In addition to SimSolid Desktop, there is also a version that is completely on the cloud. With the cloud version users can work on any device from any location and run SimSolid analyses directly regardless of computer specification (Figure 1). There are some differences between SimSolid Cloud and SimSolid Desktop, for a complete list of differences check out the comparison matrix, but one of the big differences is facet count limitations. In SimSolid Cloud users are constrained to 500,000 facets for CAD geometries, whereas in SimSolid Desktop, geometries have no limit on facet count. In today’s blog, I am going to lay out the options to control the facet count in SimSolid Cloud.

Figure 1: SimSolid Cloud Dashboard

What is a Geometry Facet?

Before we get into adjusting the facets in SimSolid Cloud, it’s important we discuss what a geometry facet is. When most geometry is created in external CAD tools, it creates a boundary representation which is shown as an edge or a surface. However, when files get imported into SimSolid, it takes those boundary representations and converts them to a geometry facet, to make the geometry handling more efficient. This facet is a small polygon or triangle and there are numerous facets in a model which represents the overall geometry (Figure 2). Therefore, if you have a highly complex model, you will have a higher facet count vs a simple model which will have a smaller facet count.

Figure 2: Example of a Faceted CAD Body

One of the cool features about SimSolid, is it enables users to control the facet count. In some cases, you might have a geometry with highly complex geometric features which requires a high facet count. In these applications, having control over the facet count is important because you may want to increase the facet count to make sure the geometry is properly represented for simulation. It should be noted that for most applications, the standard facet import option in SimSolid will import all geometries successfully.

How to Adjust the Facet Count in SimSolid Cloud:

The facets of a model in SimSolid Cloud are created during the import of the 3D CAD file into SimSolid Cloud or Simsolid Desktop. It is worth mentioning that SimSolid Desktop also has options to change the facet settings, but I am only going to show how to adjust these settings for SimSolid Cloud in this blog.  Our first step is to import a CAD file into SimSolid Cloud, I am going to use the TrueInsight Logo as our CAD file to import (Figure 3). With this logo it can be imported very easily with the standard face import option. However, I am going to adjust the facet count to be very small to show the limit where SimSolid Cloud fails to import this file.

Figure 3: TrueInsight CAD File to be Imported into SimSolid Cloud

With our CAD file ready to import, we can now login to SimSolid Cloud and import our file. Prior to importing our CAD file, we need to set the facet count. The facet import settings can be found on the left-hand side of SimSolid Cloud under the icon that looks like a gear. After clicking on that icon, the face facet import settings will pop up in the main graphical window (Figure 4).

Figure 4: SimSolid Cloud Face Import Settings

With the facet settings box open we can see there is a resolution box, as well as settings for the angular and chordal deviation of a facet. The angular deviation represents the influence of the tessellation of the curves of small radii in comparison to the overall CAD model. Whereas the chordal deviation represents the maximum distance between the actual part surface and the tessellated facet surface.

As I mentioned previously in this blog, most geometry models imported into SimSolid will import fine with the standard resolution. However, with complex models’ users can adjust the angular and chordal deviations under the custom resolution option. In our case, I am going to adjust the resolution to be customized and make the deviations very small for the facet limit to be reached in SimSolid Cloud (Figure 5).

Figure 5: SimSolid Custom Facet Import Settings for the Logo

I set values of 0.01 degrees for Angular Deviation and 0.001mm for Chordal Deviation. Note these settings are very small, and just for demonstration purposes for the CAD file to exceed the facet count in SimSolid Cloud. Changing the facet count should only be done if after the standard import setting, a user determines they want to increase the facet count to get rid of any tessellated geometry.  After applying these settings, I need to click save, and after clicking save I can import my model into SimSolid Cloud (Figure 6).

Figure 6: Facet Failure Limit Error in SimSolid Cloud for Imported Logo

We can see with the very small angular and chordal deviation values, that our geometry file exceeds the 500,000 facet threshold for SimSolid Cloud.  We are left with two options, we can either import this file with these facet settings in SimSolid Desktop since it has no limit on facet counts. Our other option is we can reduce the facet count in SimSolid Cloud, and since that is what this blog is about, we will do this option! I am now going to adjust the facet import option, by using the standard deviation settings which will have a higher angular and chordal deviation value. In order to set the standard setting, I just need to reopen the facet settings and click on the standard setting and hit save and then reimport my model (Figure 7).

Figure 7: Successful import of Logo into SimSolid Cloud

With the standard facet import resolution, our CAD file successfully imports into SimSolid Cloud! One of the other cool things about SimSolid Cloud is after you successfully import a file, you can check the facet count and how close you are to the 500,000 facet threshold. To check the facet count, you just need to right mouse button click at the top of the model tree and then left mouse button click on info (Figure 8).

Figure 8: Checking Facet Count for a Successfully Imported file in SimSolid Cloud

Immediately after clicking on info, all information pertaining to the import of the CAD file will appear. Not only will the facet count appear, but the geometry source, as well as part count, and mass properties like weight, volume and mass will be provided. Through looking at the info, we can see that with our model there are only 2748 facets (Figure 9). Remember this was done with the standard facet import settings in SimSolid Cloud.  So, we can see how with the standard setting, which is the default import setting, does a really good job of reducing the facet count!

Figure 9: Facet count of our Logo CAD file

I hope this blog has illustrated the power and ease of use in how you can adjust facets in SimSolid Cloud. If you have any more questions about Altair SimSolid or any Altair solution, please reach out to us!