VM Create Grid

Introduction

This is an excellent way of visualising check files such as the _zpt_check.mif that is written by TUFLOW. This check file is outputted after all elevation data and topography modifiers (breaklines, z zhapes etc) have been processed. This method can also be applied to other data, such as survey data to create a DEM.

Method

1. From the menu items select Vertical Mapper >> Create Grid >> Interpolation.
2. Select an interpolation method, see the MapInfo documentation for more details. For creating a DEM from a _zpt_check file I use Triangulation with smoothing.



Select Method for Grid Interpolation

3. Select the table and column for the data you want to grid.
File:VM grid interpolation2.png|none|frame|Select Data to Interpolate]]
4. Set the grid interpolation parameter, this depends on the method selected above, for triangulation of a zpt_check file, set the Maximum Triangle Side Length to be just less than your largest cell size (this ensures that you don't get triangulation across gaps in data).

5. 

   Set Triangulation Options

   
   Depending on the number of points the interpolation could take a few minutes.
   

6. Follow the prompts and set a cell size and name for the output grid. If using triangulation I set a Linear Solution.



Set Cell Size and Output Name

A grid should now be processed and displayed, to enable relief shading see this page.



Final DEM (of the _zpt_check.mif for TUFLOW tutorial module 1)