Sculpting the local terrain

The geometries are meant to be placed on the landscape. For this purpose, NDunes offers a way to smoothly integrate the geometry in the terrain.

First, the elevation tool allows to carve the terrain and modify the biome according to the geometry data. Then a selected soil can be used locally around the geometry.

The geometry elevation tool

To compute the geometry elevation, a unique button is accessible in the geometry toolbar.

Compute the elevation data

The tool computes a local elevation map according to the geometry source data.

The user has the possibility to add a special mesh defining the ground in the source data. This mesh must be named "ground". If such a mesh is found, it is used by the tool to sculpt the terrain according to it. This gives the ability to well define the interaction between the geometry and the terrain. The ground mesh can be of any shape and any height.

When no ground mesh is found in the source geometry, the tool works with a horizontal plane at coordinate 0. Its size is the geometry bounding circle size.

When generating the elevation map, NDunes asks for a fade distance. The fade is used to blend the elevation map with the landscape. It starts from the outside of the ground mesh and fades in direction of the geometry center. For this reason, the ground mesh must be large enough to contain the fade distance.

The elevation tool also generate maps used for biome density. It constrains the four types of plants and forbids their apparition inside a geometry. A different fade distance can be set for elevation and densities.

The dimension in pixels of the elevation and density maps is also an available option.


Once the maps have been generated with the elevation tool, they are accessible in the working directory in the .tif format and can be edited manually.

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Computing elevation data from the bounding circle


In this sample, we voluntarily picked the worst possible place to drop a geometry (mountain slope) and we used the bounding circle to compute the elevation. The purpose is to highlight the effect of the tool and is not very natural.

The geometry Terrain panel

Once the elevation has been computed, the Terrain panel contains some interesting informations.

The geometry terrain panel

We can see the file locations of the elevation and density maps. The Elevation file contains the height map. The Elevation weight file contains the blending map (how much of the elevation map is applied at a given position). Density files are also blending maps for each of the plant types.

In addition to the files, there are Elevation min and Elevation max values. The Elevation map stores values between 0 and 1. They are remapped between Elevation min and Elevation max.

The geometry bounding circle data (Center and Radius) are also available. The maps are centered on the bounding circle center and their size fits the bounding circle radius.

The last section of the panel is dedicated to the local soil.

Adding a local soil to the geometry

In addition to the elevation tool, it is possible to select a Soil from the list of soils in the project to apply in the elevation area. The soil is applied following the elevation weight map.

The soil default width and height can be overriden from the Terrain panel. Of course, it is better to use a soil with a default size that matches the geometry size.

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Adding local soil