Multi file (tiled) export terrain node

• Adding a Multi file export terrain node
• Exporting a terrain to multiple files
• Explanation about the formula
• Parameters

Adding a Multi file export terrain node

This node exports several files from a terrain. The images are exported as gray levels, each pixel having a value between 0 and 1. The generated images have the resolution of the terrain as its size, and the gray levels and scale of the heights (vertices with a 0 value will have their height set to the min value, and vertices with a 1 value will have their height set to the max value) determine the height of each point.

The advantage of exporting multiple files is to optimize the rendering times for very large terrains in an external engine where it is more practical to manage parts of the terrain in different files.

To add a node, right-click in the Graph Editor and select Create Node  > Export  > Multi file export terrain.

Double click on the node to open its parameters:

Exporting a terrain to multiple files

To export a terrain to multiple files, set the following parameters:

• File pattern: This is the formula used to name the files to export. The naming convention is important because the node aligns the terrain on a grid and where the first number is the X axis and the second one is the Y axis. Depending on the XY coordinates of the part of the terrain and the number of files to export, each exported file be named according to its XY coordinates, for example the top left part of a 2x2 terrain will have the name Group_0_0.png, the top right part Group_0_1.png, etc.

See Explanation about the formula for a detailed description about the formula.

Browse to the folder where want to save your files and copy the path.

In File pattern in the parameters dialog, paste the path and add a file name, for example here we add "Group" and then _$x_$y, where $x represents the position of the part of the terrain on the X axis and $y represents the Y axis.

The following pattern works for exporting to UE4: "filename_X$x_Y$y.jpg" (UE4 requires an "X" and an "Y" before the coordinates of the tile).

• File format: Choose the file format from the options available.

Format	Extension	Description
Tiff 8 bits	.tif	Tagged Image File Format
Png 8 bits	.png	Portable Network Graphics
Tga 8 bits	.tga	Truevision Targa File
Bmp 8 bits	.bmp	Windows or OS/2 Bitmap file
Tiff 16 bits	.tif	Tagged Image File Format
Png 16 bits	.png	Portable Network Graphics
Raw 16 bits	.raw	Raw Image Data File Format
Tiff 32 bits	.tif	Tagged Image File Format
OpenExr 32 bits	.exr	ILM openEXR
Raw 32 bits	.raw	Raw Image Data File Format
ARC/INFO ASCII GRID	.asc	Raster GIS File Format

• Range: Click User defined to set the Minimum height and Maximum heights or leave the default setting, Automatic.

• Size of each file: Set the following parameters:

• Click Export now to export the files.

A pop-up dialog displays the progress of the export.

Another popup-up dialog confirms the export.

The files are exported to the directory entered in the File pattern box.

Explanation about the formula

For the imported files, the node:

• Replaces $y by 0, and finds the largest value of $x that exists for the files, i.e. input_$x_0.bmp. This determines one dimension of the grid of files, called X.
• Replaces $x by 0, and finds the largest value of $y that exists for the files, i.e. input_0_$y.bmp. This determines the other dimension of the grid of files, called Y.
• The node iterates on $y and $x and calculates the image size, i.e. width and height.

Each file is loaded, and forms the corresponding part of the final terrain.

The replacement rules in the file names (or directory) are:

• $x is replaced by: 0, 1, ..., 10, 11, ...
• $0x is replaced by: 00, 01, ..., 10, 11, ..., 100, ...
• $00x is replaced by: 000, 001,..., 010, 011,..., 100,...
• $000x is replaced by: 0000, 0001,..., 0010, 0011,..., 0100,..., 1000
• $0000x is replaced by: 00000, 00001,..., 00010, 00011,..., 00100,..., 01000,..., 10000,...
• $00000x is replaced by: 000000, 000001,..., 000010, 000011,..., 000100,..., 001000,...
• Ditto for $y, $0y, $00y, $000y, $0000y, and $00000y.
• The expressions above can be used:
  • In the name of the file and in the directory name.
  • In one or more copies.
  • Mixed (for both $X and $Y).

For example:

Expression	Product names
terrain/$0x/$0y/file.bmp	terrain/00/00/file.bmp terrain/01/00/file.bmp terrain/10/24/file.bmp
terrain/$0x/$0y/file_$x_$y.bmp	terrain/00/00/file_0_0.bmp terrain/01/00/file_1_0.bmp terrain/10/24/file_10_24.bmp

Parameters

Parameter	Use
File pattern	Name and directory of the files to export
File format	Format of the files to export
Range	Sets the minimum and maximum heights of each file to export, either automatically or manually
Width and height	Sets the width and height of each file to export
Overlapping	Sets the number of rows or columns to overlap
Number of files	Non-editable parameter displaying the number of files to export depending on the graph and overlapping