Communicating Simulation with Showcase Rendering
Earlier this year, Autodesk® released an add-on application that makes it possible to render a project in Autodesk® Showcase, and include the results from Simulation CFD and CFD 360. This application is available free, and using it will be the topic of this month’s manufacturing process article, including:
- Why Render Analysis Results?
- Where Can You Get The Add-In?
- How does The Export Work?
- Importing into Showcase
- Results and Product Marketing
Why Render Analysis Results?
After many discussions with clients, developers, and manufacturing teams, the simplest explanation I can offer is that adding analysis results to your product renderings allows teams to convey complex ideas to clients and team members that might otherwise be misunderstood or even dismissed. Additionally, some creativity applied to the environment in Showcase can create beautiful results that can be used to market your products in a new way.
Where Can You Get the Add-In?
The application is available from the Autodesk Exchange App store here:
Autodesk Exchange Simulation Section (http://goo.gl/ibN9J)
Figure 1: Simulation section of the Autodesk Exchange site.
Once installed, the add-in populates a new tab in the simulation software, titled Add-Ins.
Figure 2: Add-Ins tab in Simulation CFD 2013.
Figure 2 shows how the Showcase Panel (and the Export FBX) is added to a portion of the Results tab contents in Simulation CFD. From this Add-Ins tab, most results visualizations can be added and adjusted prior to exporting your FBX file. This is kind of a handy feature—rather than simply adding an export button.
How Does the Export Work?
The Export FBX button creates objects that can be imported into Showcase, which can then be applied to the rendering project.
Figure 3: The Showcase Export dialog.
Once initiated, the Showcase Export dialog will appear with fields that permit users to change the storage location of the FBX file, the number of trace sides, and the output units. I usually store these files with the Showcase project.
Figure 4: Simulation CFD results.
Each component (Traces, Planes, etc.) are packaged up in the single file, but will continue to be controlled separately in Showcase.
The Units are quite important. These act similarly to Fusion where, if not selected properly, will result in a coordinate and size mismatch that you will have to adjust in one manner or another (such as scale and translation).
The number of trace sides is still somewhat of a mystery, except that it will jack up the size of the file immensely. What it appears to do is to create an overlay of data that has something to do with visualization. The default settings were routinely producing 20MB files (depending on the amount of trace data), so watch this carefully.
Importing into Showcase
Models can be imported into Showcase by the Import tool found in the Application menu. Once selected, Showcase will import and convert the data to a native format, and then add it to the environment.
Figure 5: The Showcase Organizer.
Figure 5 shows the export that I created called Traces1.fbx. Notice how the Mesh and Lines are separated (these represent the plane and traces results I created in Simulation CFD). I have suppressed the plane, but left the traces visible.
Note: Translating models in Showcase is not super-user friendly. Typically we do not have much need to do so, as the information is transferred directly from the assembled products in Inventor and Fusion and straight into Showcase. However, should the units not match between the imported results and the Showcase environment, some translation and scaling will need to be applied. In my case, once I corrected the units on the export, some translation was still necessary. I simply used the dialog and drag arrows to maneuver the traces into the correct position.
Figure 6: Translating the imported results model.
I’ll focus on traces for the remainder of the article, but note that I have created some good overlays with the planes.
Thickness of the Traces
The thickness of the traces is applied in the Simulation CFD Trace List dialog. Once exported, there is nothing that can be done to adjust this in Showcase.
I found that 10mm or thinner traces produce better results in large environments, especially where geometry is more important than conditions. Generally, greater quantities of thinner traces produce better results.
However, where very clear viewing of the results contours is necessary, 10mm to 20mm traces do better.
Additional styles are available as well. The default style shown here is ‘Cylinder.’ Another useful one to try is ribbons. There are about 10 styles to choose from. Try different styles and render them with different properties until you find the effect that works best for you.
The default material that comes in with the import is the one named ‘Material.’
Figure 7: The adjusted material type. Note the original imported ‘material’ icon appearance that lies above and to the right of the dialog.
In some cases the imported material type is fine; however, in this example, I needed to adjust some parameters to get the effects desired.
This truly requires a delicate balance, as the more transparency that is applied, the more the result colorations are washed out.
I thinned the shadows down a bit, and limited the distance that they would cast. Initially the walls were filled with shadows, but this is not the effect I needed.
Refraction was a great blessing for the traces, and allowed the ray-tracing to work some magic (see Figure 8). I tried numerous methods before settling on that shown in Figure 10.
Figure 8: Heavy refraction applied to thicker traces. This was eventually discarded, but you can see the possibilities.
I also came back and added a touch of reflection in order to give these an appearance of dimension.
The following images are the final result of the room render we developed at Design & Motion for the Autodesk University class.
Figure 9: Showcase hardware rendering.
Figure 10: Showcase ray-tracing with 15 iterations.
Results and Product Marketing
In the previous example, it is very difficult to produce understandable results and render the image effectively. This is simply the nature of a large, spread-out frame, attempting to view both the results and the environment from inside the stream. The only way to convey this scene with easily viewable trace contours (original simulation colors), is to render multiple frames from different angles. However, when looking at more concentrated traces against a smaller target, it is much easier to visualize the results in a rendered environment from a single view.
Figure 11: Turbocharger Velocity results in cutaway housing and glass styled impeller.
In Figure 11, the housing has been cut away, and the impeller material property changed to glass. The results were left unchanged, in order to relate the pertinent information contained in the colored contours. It is easy to understand the relative velocity changes as the airflow is accelerated across the impeller, but slows as it is compressed along the outer edges of the housing.
This is a powerful add-in, and is really limited by your imagination. Varying trace styles and sizes along with various material and environment strategies can produce vastly different visual effects that can be tuned to the need or mood of the viewer.