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You can do this with a filter node: Select the Surface plot node. Right-click and select Filter from the context menu. In the Filter node's settings, you enter a logical expression that selects the domain that you want to evaluate. E.g., to only evaluate in the positive octant, you can enter (x>=0) && y>=0) && (z>=0). The boundary between the region that is evaluated and the region that isn't might become jagged as the filter node operates on elements.

First of all thanks for the reply.

My temperature data is located in the domain of 0<x<0.593 m, -0.25<y<0.25m, and 0.055<z<0.105. I try to fill the filter expression: (x<=0.2) && (y<=0) && (z=0.08), but a "Syntax error in expression" error came out. Did I do something wrong?

My temperature data is located in the domain of 0<x<0.593 m, -0.25<y<0.25m, and 0.055<z<0.105. I try to fill the filter expression: (x<=0.2) && (y<=0) && (z=0.08), but a "Syntax error in expression" error came out. Did I do something wrong?

Multiphysics' comparison operator is ==, not =, so you have to replace "z=0.08" with "z==0.08". In your case, the expression (0<x) && (x<0.593) && (-0.25<y) && (0.25<y) && (0.055<z) && (z<0.105) should do the trick.

Oh I see! Everything okay now. Thanks a lot!

The filter node seems like kind of a clunky way of accomplishing selective results display in post-processing. It is fine if your geometry is simple but what if you have complicated geometric features? There should be a way to create a nodal selection based on a surface (any modeled surface) and then plot only these results, or at the very least a way to hide unwanted surfaces in a 3D surface plot. Anyone know a workaround for this?

Hi,

There are a couple of things that you can do to hide surfaces or to plot only on some surfaces:

- Under the View node (typically Component>Definitions>View), add a Hide Geometric Entities node, where you can specify which entities to hide, such as boundaries (surfaces) in a 3D model. The boundaries that you add to the Geometric Entity Selection in the Hide Geometric Entities node's settings window are then hidden for that view when you plot 3D results, for example.

- Under the Results>Data Sets node, for the data set (such as a Solution data set) that you plot, add a Selection subnode, where the default selection is the entire geometry, but you can choose to include only some domains or boundaries (depending on the type of plot). The plots using that data set then only include the selected geometric entities.

Best regards,
Magnus Ringh, COMSOL

Hello,

Here are a couple more resources for what you were asking about, Matt. These pages give a good rundown of how to plot a solution on only the surfaces you want selected, how to hide different parts of a component, etc:

How to include different surfaces in results plots: www.comsol.com/blogs/include-geometry-surfaces-solution-plots/

Short videos that give an overview of advanced visualization techniques (they are from 4.3b, but the information still applies): www.comsol.com/blogs/advanced-visualization-techniques-in-postprocessing/

Several shortcuts and tricks using the Graphics window (the last section discusses the view and selection features that Magnus mentioned): www.comsol.com/blogs/the-graphics-window-effective-beautiful-postprocessing/

Regards,
Lexi Carver, COMSOL

Thank you both for your replies. I knew there had to be a better way.