# Surfaces

ResInsight is capable of mapping properties and simulation results onto 3D surfaces imported from GOCAD and Petrel as specified below.

## Import and appearance of surfaces

3D surfaces from GOCAD and Petrel are imported into ResInsight by the menu option File->Import->Import Surfaces in the 3D Main Window.

Imported surfaces are listed under the entry in the Project Tree. You can click on a surface to change i.e. the name or color of the surface, or change the file to read the surface data from.

You can also change the depth of the surface by adding a depth offset (positive or negative). This could be used i.e. to import the same surface file multiple times and assign each instance of the surface a separate depth offset. When a depth offset is set, the offset value will be shown as part of the surface name in the project tree.

## Using folders

To make it easier to organize the surfaces you import into your project, ResInsight supports creating surface folders in the project tree. To create a new folder, right-click on the top level Surfaces folder in the project tree and choose Add Folder.

## Surface Results

Per default, ResInsight maps current Cell Result on a given surface. If another result is to be displayed, specify the result under Surface Results as shown below.

Clicking a surface of a View in the Project Tree activates the Property Editor for allowing view settings as shown below.

To change result displayed on the surface, please specify the desired result in the Result Reference section of the Property Editor.

If you have modified a surface file using an external program, you can easily load the changes into ResInsight by using the reload surface feature. Bring up the right-click menu for the surface you want to reload and choose Reload. The views will automatically update with the new data (could take a few seconds).

## Create a copy

You can easily create a copy of an existing surface by choosing Create Copy in the surface right-click menu. A new, identical surface will show up at the same level in the project tree. You can now give it a new name, change depth offset etc.

## Grid Case Surfaces

In addition to importing surfaces from file, ResInsight can also generate grid case surfaces. You do that by bringing up the right-click menu for the project tree entry and choose Create Grid Case Surfaces.

A grid case surface has the same properties as a surface imported from file, but instead of choosing which file the data should come from, you choose a source case, a slice direction and a slice index. The slice direction and index will be added to the surface name shown in the project tree.

## Exporting Surfaces

ResInsight can export surfaces to the GOCAD TSurf file format. Grid case surfaces can additionally be exported to Petrel Surface PTL format. Use the right-click menu for the surface you want to export and choose the export format you want to use. A file selection window will show up allowing you to choose where you want to save the exported data.

## Supported Surface Formats

GOCAD is a computer application that allows you to import, create, modify, integrate, view, and export geological objects in 3D. The GOCAD export file format supported by ResInsight is TSURF (*.ts). A TSURF data file is a triangle based surface format containing vertex coordinates and triangle to vertex connectivities as exemplified below. ResInsight import vertex and triangle identifiers from the first TFACE section in such a file.

GOCAD TSurf 1
name:MF_027_SU
}
NAME Default
AXIS_NAME "X" "Y" "Z"
AXIS_UNIT "m" "m" "m"
ZPOSITIVE Depth
END_ORIGINAL_COORDINATE_SYSTEM
TFACE
VRTX 1 458177.767090 7322538.712891 1643.655884 CNXYZ
VRTX 2 458260.834961 7322392.890625 1596.685303 CNXYZ
VRTX 3 457985.662109 7322783.783203 1542.060059 CNXYZ
VRTX 4 459601.453125 7322511.427734 3639.000000 CNXYZ
VRTX 5 459422.015625 7322689.230469 3639.000000 CNXYZ
VRTX 6 459793.410156 7322338.230469 3639.000000 CNXYZ
...
TRGL 2 61 98
TRGL 20 153 66
TRGL 152 19 65
END


### Petrel Surface PTL files

ResInsight is capable of importing a surface defined by a PTL (*.ptl) file from Schlumberger Petrel. A PTL data file specifies the quads of a surface by x, y, z nodal coordinates and the i and j indices as exemplified below. As seen, # denotes comment lines.

#Type: scattered data
#Version: 6
#Description: No description
#Format: free
#Field: 1 x
#Field: 2 y
#Field: 3 z meters
#Field: 4 column
#Field: 5 row
#Projection: Local Rectangular
#Units: meters
#End:
#Information from grid
#Grid_size: Not_avaiable
#Grid_space: Not_available
#Z_field: z
#Vertical_faults: Not_available
#History: No history
#Z_units: meters
443479.500000 7305390.500000 -1000.000000 1 1
443479.500000 7305488.500000 -1000.000000 1 2
443479.500000 7305586.500000 -1000.000000 1 3
443479.500000 7305684.500000 -1000.000000 1 4
443479.500000 7305782.500000 -1000.000000 1 5
443479.500000 7305880.500000 -1000.000000 1 6
...


### OpenWorks XYZ Surface files

ResInsight is capable of importing a surface defined by a XYZ (*.dat) file from OpenWorks. A XYZ data file specifies the quads of a surface by x, y, z nodal coordinates organized in a regular grid. As seen, # and @ denotes comment lines.

@File_Version: 4
@Coordinate_Type_is: 1
@Export_Type_is: 1
@Number_of_Projects 1
@Project_Type_Name: , 3,xxx,
@Project_Unit_is: meters , xxx
#File_Version____________-> 4
#Project_Name____________-> xxx
#Project_Type____________-> 3
#Export_XY_Unit__________-> meters
#OpenWorks_Project_______-> 'xxx'
#Master_Project_______->
#Coordinate_type_________-> 1
#Number_of_points_in_hzd_-> 1
#Horizon_internal_id_____-> xxx
#Horizon_extremes_are____-> xxx,xxx
#Horizon_onset_is_Minimum_____-> 1
#Horizon_type_is_DEPTH_STRUCTURE______-> 2
#Horizon_color_is________-> 255 0 0
#Horizon_name____________-> xxx
#Horizon_attribute_______-> DEPTH_STRUCTURE
#Horizon_version_________-> UNKNOWN
#Horizon_interp_status___-> defaultStat
#Horizon_class___________-> defaultClass
#Export_Z_Unit___________-> meters
#Horizon_onset_type______-> Minimum
#Horizon_data_domain_____-> DEPTH
#Horizon_remark_size_____-> 50
Horizon from Grid on Fri Aug 14 13:42:10 CEST 2020