PolyPaint from Thickness

PolyPaint from Thickness

Evaluate distance between the outer and inner walls of a surface intended for 3D Printing and manufacturing

The From Thickness feature gives you the ability to evaluate the distance between the outer and inner walls of a surface intended for 3D Printing and manufacturing. This information is essential for identifying where corrections might be necessary in the sur­face areas on the model before final output for manufacturing.

Example of a model with PolyPaint from Thickness applied

How PolyPaint From Thickness Works

When evaluating safe distances for meshes with wall thickness, ZBrush uses sliders and parameters to process the inner and outer shell surface distances. It then applies PolyPaint across a spectrum of 7 colors, displaying a distance range from the desired minimum to maximum distance values.


From Thickness Functions


By default, the Min & Max Range slider values is an internal number that does not indicate any specific system of measurement. To assign a system of measurement to these units the scene will need to be pre-scaled and imported into ZBrush using the Scale Master plugin. Alternatively, you can use the Scale Master plugin to Set Scene Scale directly in ZBrush. (See the PolyPaint from Thickness in Action section, below.)

Quality Slider

Controls the number of rays cast from each polygon when evaluating the faces around it.
Setting this to higher values directly controls how accurately the PolyPaint analysis colors will be displayed on the surface.
The higher the number of rays cast, the more accurately the PolyPaint colors will represent the wall thicknesses based on the Minimum Range and Maximum Range fac­tor settings. Of course, this increased accuracy will come at the cost of longer computation times.

Max Range Slider

Sets the desired maximum distance factor for wall thickness between the inner and outer shells.
This slider directly controls the gradients of color analysis PolyPaint (7 total) dis­played on the model. Having a higher range between Max Range and Min Range will display more analysis colors for more accurate representation of surface distances be­tween the minimum and maximum range factors.

Min Range Slider

Sets the desired minimum distance factor for wall thickness between the inner and outer shells.

Preferences >> Analysis (PolyPaint Color Spectrum)

These color patches allow you to set the 7 colors that will be used when displaying the spectrum on the mesh, based on the Minimum and Maximum Range settings.

How Color Analysis S – C5 Slots are Calculated

1. Minimum Range x Maximum Range = Range Threshold.

2. Range Threshold / 6 = Incremental Slot Amounts (Slots S – C5).

*Slot E is reserved for any surfaces that exceed the maximum range factor.

The colors listed below for each slot are the defaults.

    • S (Red) – Below the Minimum Range distance factor and therefore considered to be an unsafe thickness.
    • C1 (Pink) – The Minimum Range value.
    • C2 (Yellow) – 1 increment of distance beyond Minimum Range.
    • C3 (Green) – 2 increments of distance beyond Minimum Range.
    • C4 (Light Blue) – 3 increments of distance beyond Minimum Range.
    • C5 (Purple) – 4 increments of distance beyond Minimum Range.
    • E (Blue) – Exceeds the Maximum Range factor and therefore considered to be a safe wall distance (but only when Minimum Range is the primary factor).


When Minimum Range for wall thickness is considered the primary factor for adjustments; Red areas will need additive sculpting or adjustments in order to exceed the Minimum Range distance from the inner wall.

When Minimum and Maximum Range for wall thickness are both considered as primary fac­tors for adjustments, Red and Blue areas will need additive or subtractive sculpting/adjustments to meet the safe distances for Minimum and Maximum Range.

Polypaint From Thickness in Action

Begin by creating a mesh that has wall thickness and pre scale a scene with Scale Master Plugin to complete the full procedure for using PolyPaint from Thickness.

1. Open Lightbox\Projects\DemoAnimeHead.ZPR.

2. Select IMM Primitives Brush to begin creating a shell for the DemoAnimeHead.


3. Select Insert Sphere from the IMM brush menu, and disable symmetry.

4. Alt+Drag onto the mesh head to apply a subtractive action.

5. Turn on Gizmo 3D, then completely move the inserted sphere outside of the head mesh.


6. Ctrl + drag outside the mesh once to clear the mask.

7. Set the Geometry >> DynaMesh >> Thickness value, then click Create Shell.


8. Set Scene Scale with Scale Master Plugin by clicking ZPlugin >> Scale Master >> Set Scene Scale.



For this example, we will configure the head to be 127mm tall (5 in).

9. Choose 1.42 x 2.00 x 1.46 in.


10. Scale Master >> Set Y axis value to 5. Click enter.

11. Click the Resize Subtool button. This will now update the scale of the model.



Skip steps 12 & 13 if you do not wish to update the scene factors to Millimeters.

12. Click Set Scene Scale again.

13. Choose 90.43 x 127 x 92.46 mm



Applying steps 12 & 13 will allow you to associate the PolyPaint from Thickness slider values to desired units of measurement.

14. In the Tool >> PolyPaint sub-palette, set Min Range to 1 and Max Range to 5.



These values will be calculated in inches or millimeters if you’ve applied steps 12 & 13.

15. Click From Thickness.

From Thickness results

16. When examining the mesh at this point, all red surfaces will need to be modi­fied as they are below the minimum wall distance and therefore too thin for safe printing.


PolyPaint Analysis Colors at current scale factors:

    • S (Red) – below 1 mm wall distance
    • C1 (Pink) – 1 mm wall distance
    • C2 (Yellow) – 2 mm wall distance
    • C3 (Green) – 3 mm wall distance
    • C4 (Light Blue) – 4 mm wall distance
    • C5 (Purple) – 5 mm wall distance
    • E (Blue) – Exceeds 5 mm wall distance


Try using the Inflate or ClayBuildup Brushes to adjust the thickness. Be sure to turn on the Backface Masking option to protect the inner wall surfaces.


17. Click ‘From Thickness’ again to re-calculate the changes made to outer wall thickness.

The final result