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Thickness analysis measures how much material is distributed throughout each region of a part.

Currently, only native Onshape parts and mesh model types are supported. Closed composites are not currently supported.

Steps

In a Part Studio that contains at least one part:

  1. Click the Show analysis tools () in the bottom right corner of the graphics area. From the menu, select Thickness analysis to open the dialog box:

    Thickness analysis tool dialog box

  2. Select a part (or parts) to analyze.

    Onshape instantly begins to compute the thickness analysis request. The progress spinner in the bottom left of the graphics area provides an update on the status of the analysis:

    • Preparing thickness analysis - Geometry is discretized and processed for analysis

    • Processing thickness analysis - High performance cloud instances are provisioned

    • Calculating thickness - Thickness analysis computation begins

    • Refining thickness analysis - Initial results are available and higher fidelity results continue to process

    • Postprocessing thickness analysis - Final results are processing and will soon be available

  3. Click the green check mark to accept your selection and close the dialog box. The thickness analysis tool stays active. When the initial thickness analysis results are available, the color bar opens in the graphics area:

    Thickness analysis color scale

    Selected parts automatically render. The color bar maps field values to the colors displayed along the surface of your part (or parts).

  4. To change the color scheme, select a palette from the Colors dropdown.

  5. To change the color bar's range, select either the lower or upper bound value and type in a new number. Use the refresh button to reset the bound to the lowest/highest value within the measured field.

    Alternatively, click and drag the tick mark above either the lower or upper bound value and drag it to a new position along the legend. Reposition the color bar entirely by hovering your cursor until it becomes active, then click and drag the legend to a new position on your screen.

    Unless manually adjusted, the legend's bounds may automatically adjust to new limits while intermediate thickness analysis results are refined. Once manually adjusted, intermediate updates will not cause the upper or lower bounds to change. However, the far-most values along the color bar may update as new information becomes available.

    The legend shows unique colors for field values outside of the user-defined bounds. Check the Dim colors scale option to create a 3-color view and quickly assess regions outside of your target range.
    Screenshot of the Thickness analysis color scale with Dim color scale option checked

  1. Select the preferred field from the Method dropdown menu:

    • Rolling ball

    • Rolling ball gradient (%)

    • Ray

    • Ray gradient (%)

    You can continue to work in the Part Studio normally while using Thickness analysis. The thickness evaluation will automatically update as you make edits.

  1. To edit the Thickness analysis, click the Show analysis tools () in the bottom right of the graphics area and select Edit thickness analysis from the menu.

  2. To turn Thickness analysis off, click the Show analysis tools () and select Turn thickness analysis off.

Rolling ball thickness method

The rolling ball thickness method calculates the size of the largest sphere that can be inscribed within a part at each point along the part's surface.

The sphere is tangent to the point of inspection and at least one other point upon the part (though it may be tangent to more than one part) and is thus said to roll along the part's interior while simultaneously changing size. The thickness measured is reported as the diameter of the inscribed sphere.

Thickness analysis Rolling ball method example

Tips

  • The rolling ball thickness method provides a thickness measurement defined by localized, non-trivial geometric relations at more than one point within the region of interest.

  • The rolling ball thickness distribution is guaranteed to be continuous across all regions of any solid part.

Ray thickness method

The ray thickness method calculates the distance traveled along a straight line path through the interior of a part.

At each point along the part's surface, a ray is projected normal to that surface, terminating upon first intersection at another point along the part. The length of the line segment between those two points is the ray thickness.

Thickness analysis Ray method example

Tips

  • A line projected normal to one point along the surface of a part has no guarantee of any geometric relation to the surface at its second point.

  • The ray thickness distribution is seldom continuous across the entire part. It will contain sharp discontinuities, most obviously near sharp corners.

Thickness gradient (ray method or rolling ball method)

The thickness gradient method measures how quickly the thickness of a part changes as one moves along the part's surface. The value itself is the ratio (A/B) of the following terms:

  1. The maximum amount that thickness could grow or shrink as one moves (nominally and instantaneously) in any direction from one point along the surface of the part, measured in units of length.

  1. The nominally instantaneous geodesic distance traveled along said direction, measured in the same units of length.

The ratio is non-dimensional, non-negative, and presented as a percentage (%) out of convention.