How to use the Sketch on Planes tool
with MicroScribe.

solidThinking allows you to use MicroScribe according to two main methods:

  • standard points input;
     
  • sketch on planes, allowing you to move the MicroScribe arm over a physical model and create point clouds on parallel planes.

     

In this simple tutorial we will see how to use this second method to reproduce a chalky corrective bust.

Before starting to get data from the MicroScribe, you must first activate and calibrate it.

The model is courtesy of A.Tirelli

 

 The model is courtesy of A.Tirelli

To activate the digitizer, choose the Managers>Devices menu item. A dialog box appears allowing you to select the proper baud rate and serial port. The default Baud Rate is generally the proper one. In the Com Port section you can specify the COM port attached to a serial socket on your PC. Confirm settings by pressing OK.


Calibration allows you to make the MicroScribe coordinate system correspond to the world coordinate system of the solidThinking scene. To calibrate, choose the Tools>Digitizer>Calibrate MicroScribe menu item. The program console will prompt you to specify the following:
- Origin Point. Pick a point on or near your physical model that will be the origin of the MicroScribe coordinate system.
- X Axis. Pick a point on or near your physical model that is on the X axis of the MicroScribe coordinate system.
-
Y Axis. Pick a point on or near your physical model that is on the XY plane of the MicroScribe coordinate system.
- Scale. Type the scale factor or confirm the default value. This factor is applied directly to the points from MicroScribe obtaining a different size for your physical model.

Now we are ready to use the Sketch on planes tool allowing you to process the points from MicroScribe input and create point clouds containing points that lie on parallel planes. As long as the command is active you can press the MicroScribe button and send the position point to solidThinking by moving the arm over the physical model. If you need to change planes parameters or distances parameter, release the MicroScribe button, set new parameters and press the button again to start another section.

Click the Sketch on planes icon or choose the Tools>Digitizer>Sketch on planes command.

The program console prompts Origin, i.e. the point defining the position of the first plane.

In the Modeling Tool panel you can interactively modify other parameters. This way it is easy to obtain the planar clouds which better describe the original object shape.

Every time we press Create planes,
we create new planes according to parameters. This way you can create planes with different settings and steps. If you need to delete the just created group of planes press Delete new planes.

The Snap to plane tol. parameter controls the point distance to plane. If a point from MicroScribe has a distance to a plane lower than this, the point will be projected onto the plain and inserted in the plane cloud. This tolerance is very important for an accurate model reproduction, but if it is too low, planes could not intercept points sent from the MicroScribe.

The Min. dist. between points parameter controls the minimum distance between points lying on the same plane. When the distance from a projected MicroScribe point to other points on the same plane is higher than this parameter, the point is inserted on the plane cloud.

This tolerance is very important to control imprecision due to manual use of MicroScribe and to create planar clouds with a limited number of points. The higher this parameter, the lower the number of points of the planar cloud.

 

 

 

 

 


Now we are can rebuild the surface.

Choose the Tools>PointsCloud>Curve from PointsCloud menu item and create curves from the planar clouds paying attention to the point representing the start of the curve.

If you want solidThinking allows you to reduce the number of points of a surface given a specified tolerance. The purpose is to simplify the surface while maintaining its shape in the specified tolerance.

The Skin modeling tool allows you to create the surface using these curves.

We are finally ready to render our model.

 

Live demo (2.56MB)