Ground Texture

A Ground Texture param allows you to map a new texture onto the terrain generated by the OCAD converter.

The primary layer is the main texture layer.  Its default texture is a grayscale map that is shaded based on terrain angle and the canopy shadow.

On top of the base texture, you can blend a detail texture for higher resolution ground details.  The default ground (see symbol 405.0) uses the default grayscale base texture, with a green leaf detail texture blended in for color and texture.

When changing the primary layer, you can set the base texture, the detail texture, or both.

The blended layers allow for additional layers to be applied on top of the primary layer.  These layers are rendered with an alpha blend enabled, so they can use an alpha channel to smoothly blend with any type of primary layer.

An example of blended layers is in the footpath symbol (506.0). It uses a blended texture to add a sandy path on top of the texture below it.  The edges of the path texture have reduced alpha, so the path blends smoothly into the primary layer below.

A special mode is used for trails and paths: Linear Texture Coordinates. Symbols that specify this option must be inside a LineToArea symbol. The converter will then assign the texture coordinates in increasing order along the line.