The base of a 3D surface in Surfer is drawn to the minimum Z value of the grid file. To adjust this, you need to adjust the minimum Z value of the grid file. To do so:
- Right click over the 3D Surface layer in the Contents window and click Edit Grid.
- In the Grid Editor, the lower left node is selected. That’s fine. In the toolbar, in the Z box enter the z value you wish the base to be drawn to (e.g. -200).
- Click Grid Editor | Options | Update Layer.
- Click File | Close to close the Grid Editor.
- Click No, in the Surfer dialog asking if you want to save the changes to your grid file (you don’t want to actually change the grid file).
- Back in the plot window, as long as the Z axis is showing automatic scaling, the base is now drawn to the new minimum Z value.
Email firstname.lastname@example.org if you would like to add your vote to our suggestion file for the ability to define a custom z value for the base to be drawn to.
Updated October 24, 2017