Point Cloud to Exact Surface output
Objective: Starting with a point cloud, work through the Point phase, Polygon phase, and Exact Surfaces phase to output a non-parametric IGES or STP model. Approximately 15 minutes. CV_Joint.wrp
Time Required: File:
Open CV_Joint.wrp. This is a point cloud generated from scan data of a CV joint.
This is scan data of aCV joint, taken with a laser scanner. Using Geomagic Studio, you will see the process of converting this point cloud into a CAD-ready surface model in about 15 minutes. The process involves three basic types of entities: points, polygons (or triangles), and surfaces. We will begin with points. Most scanners produce some level of noise, which is commonly due to shiny or reflective surfaces. TheReduce Noise command can minimize the problem by identifying noisy points and moving them to the local average surface to improve the
Navigate to the Points tab and click on Reduce Noise. Select the Prismatic shapes (aggressive) mode Set the Smoothness level to Min. Click Apply and then OK.
Click on Wrap under the Points tab. Accept the default settings and click OK.
Thenext step is to “wrap” the point cloud, which generates a blue triangular mesh between the points. This mesh can be modified in a number of ways. You can fill in holes, smooth out rough areas, remove unwanted features, and even add features to it.
Navigate to the Polygons tab and click on Fill All. Select the Tangent fill type and click Apply. Both of the holes in the model have been filled.Click OK to exit.
The hole filling command one of the most powerful tools in Geomagic Studio. The Tangent fill specifies that the new mesh must match the curvature of the surrounding mesh.
Use one of the Selection tools (i.e. Lasso, Rectangle, etc.) from the right-hand menu to select the part no on the model. Click the Defeature icon.
The Defeature command is great for quickly removingunwanted features or imperfections.
Select the Display tab and check ON the World Axes. Zoom out and rotate the model to see its position relative to the world coordinate system.
When a part is scanned, often it will not be in the desired position relative to the World Coordinate System. To visual the current position, the World Axes can be checked ON in the Accessories area under the DisplayTile.
Use CTRL-R to reset the rotation center to the center of the model bounding box and orient it on screen to its original position.
Resetting the rotation center to the mass center of the part will also reset the original on screen position, often making selections easier.
Navigate to the Features tab and click on Plane > Symmetry. From the Define menu, select Line Click and drag(like in the picture below) roughly along the line of symmetry Click Apply and Studio will locate the symmetry plane. Click OK
Features can be used for a variety of tasks including alignments, references for downstream CAD geometry construction, and location references for Studio functions such as CrossSection creation and Section by Plane.
Click on Line > Cylinder / Cone / RotationalAxis. Select the Rotational Axis radio button Using the Rectangle tool and Select Through , select the region of the model indicated in the picture below Click Apply and then Next Use the Flip Orientation button to orient the axis so that it points upward (if necessary) Click OK
Now we will align the model to the world coordinate system. Navigate to the Alignment tab and click onAlign to World.
Several alignment options are available within Studio including Best Fit, Feature Alignment, RPS Alignment, and Alignment to World. This affords a great deal of flexibility to correctly orient the model for downstream applications. When using Alignment to World in Studio the primary planes and axis in World are predefined so Feature planes and axis in a part can be...