This tool is used to detect areas of your model that might not be printable without supports (we call these areas “overhangs”), and to automatically generate supports to make your model printable. 

We determine overhangs by looking at the angle between the surface normal vector at a point and the downward direction (negative y) vector. If the surface normal is pointing in approximately the same direction as the downward vector, this point is identified as an overhang.

Overhangs are rendered in red, with the boundaries of overhang regions shown in blue.


Basic Parameters

  • Angle Thresh: if the angle between surface normal and downward vector is less than this value, we consider the surface to be an overhang
  • Contact Tol: tolerance for detecting if a face is already resting on the ground plane. If a face’s height is below this tolerance, we won’t consider this face when determining overhangs
  • Y-Offset: distance from the ground plane to the object. Set this to produce a print that is elevated off the print bed by supports, rather than resting directly on the bed.

Support Generator

These options control how the supports are created. Supports are comprised of networks of cylindrical segments called “posts”. The topmost segments (attaching to your model) we call “tips”, and the bottommost segments (resting on the print bed) are “bases”.  See the labeled diagram.


  • Max Angle: maximum draft angle of generated support geometry
  • Density: controls the spacing between supports
  • Layer Height: the layer height of your printer
  • Base, Post, and Tip Diameter: Specify the diameter of the supports at print bed level (base), where it connects to the model (tip) and the space in between (post).


Advanced Support

Allow Top Connections: if checked, allows a support base to be located on the model itself. If unchecked, all support bases will be on the ground plane.

Optimization: the support generator will try to optimize build time by placing the supports close to the printed object. This value controls how much of this optimization is performed.

Solid Min Offset: allows you to set a “buffer zone” around the object when performing the Convert to Solid operation (see below). This value controls the distance around the object in which no solid support will be created.

Tip Height: height of the topmost segment of the support

Base Height: height of the bottommost segment

Strut Density: controls how many posts can be connected to each “fork” in the network of supports

Post Sides: number of flat facets used to approximate the cylindrical post geometry.


You can use Generate Support and Remove Support to create and delete the set of supports. You can also manually add supports by clicking and dragging from an overhang to the ground, or from an existing support base to an overhand on the model. To delete a support, CTRL + click on it (CMD + click on Mac).

Convert to Solid: transforms the generated supports into scene geometry. You can choose to either add the supports to the existing object, or create a new object.