Point Cloud to Mesh. 1. Click on the Index/Attach command icon in the toolbar to open up the parameter setting panel on the right side of the screen.

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1 Point Cloud to Mesh Objective: Learn how to use point cloud clean up and triangulation tools to generate a high quality polygonal model in VRMesh. The following instructions will take you step by step through the general procedure of point cloud triangulation. Step 1: Import file There are two commands that can be used to read a point cloud file (*.txt, *.asc, *.xyz, *.las, *.pts, *.ptx, *.dxf). The Import command (File > Import) imports all data into the window. The Index/Attach command (File > Index/Attach) allows you to create an index file from a point cloud and attach it to the current project, which only retrieves inquiring points into the window. Depending on your computer setting, you may choose to index/attach a point cloud file into the window if it contains more than 3 million points. In this tutorial, we use the Index/Attach command to load a sample file that contains more than 10 million point clouds into the window. 1. Click on the Index/Attach command icon in the toolbar to open up the parameter setting panel on the right side of the screen.

2 Press the [Index] button. A dialog box is opened to allow you to choose a name, directory, and file type for the file. The program will create an index file with a *.PCP extension saved to the same folder as the original file. Please note that the Omit partitions along Z axis checkbox should be unchecked because our sample data is not from an airborne/mobile LiDAR. 2. Once the indexed PCP file has been created, you are ready to attach it into the window. The Point Cloud Density slider controls the number of points (density) displayed on the screen. Move the density slider to increase/decrease the amount of points and press the [Reload] button or F2 to reload the point cloud data. The maximum number of points that can be displayed on the screen is 3 million. The attached file appeared in the Object Tree Window will be marked with an asterisk, e.g., *Object. Step 2: Convert Point Clouds to Meshes Open up the Point Cloud to Mesh wizard by clicking the icon or from the Cloud menu. Specify the data file you want to process. The Current File option allows you to process the current dataset displayed in the window. The Files in Folder option allows you to process all files in a specified folder. We choose the Current File option in this tutorial. Select the commands you want to execute. Press one of the Setting buttons to open up the corresponding parameter setting panel on the right side of the screen and adjust the value of parameters for each selected command.

3 1. Decimate Point Cloud Choose the Uniform distribution type, which makes more uniform distribution of points on flat regions than the "Non uniform" type. Set the number of Remaining Points to 3 million, which will generate around 6 million triangles. Set the Curvature Weight to 0.3. The higher the curvature weight, the more points will be kept around edges.

4 Note: We have reduced the number of points to 3 million in this example, which is smaller than the pre defined threshold of Max. Points for This System located at the System parameter setting panel (View > System > others). Therefore, the program will automatically load all points in the index file into physical memory for the following point cloud and mesh processing steps, instead of processing each block from the index file one by one. The default threshold is set to 4 million. You may adjust the threshold according to the physical memory on your computer. 2. Denoise Point Cloud The Smoothing Weight specifies smoothing constraints for sharp edges and corners. The higher this value, the less sharp edges and corners will be affected. The Smoothing Iteration defines the number of iterations for smoothing. Depending on how much noise is present in the point clouds, this step may not be necessary. 3. Point Cloud to Mesh This step automatically converts point clouds to triangle meshes. No specific parameters are needed. 4. Remove Floating Parts This step deletes small sub objects according to the connection of meshes. The Min. Number of Triangles defines the minimum number of triangles required for a valid part.

5 5. Decimation This step reduces the number of triangles while maintaining a good approximation to the original geometry. We set the remaining triangles to around 500,000 in this example. Press the [Apply] button in the wizard after all parameters above have been set up. The program will execute the selected commands step by step. The final model is shown below: