Volumes

Height fields

From Height Fields to COPs and back

Document here how to go from the two context, the quirks and

Basics

Hfs are 2d volumes!! Texturing Landscapes for Games

Delete all fields except height and masks

Using a delete node, in the grp expression write:

hscript

// Run as a group filter
^@name=mask ^@name=height

Sample a heightfield mask

Heightfields have an internal height, make sure to have the heightfield at the origin

vex

//run over points
// input 0: points
// input 1: heightfield
// Heightfield = 0
vector local_pos = set(@P.x, 0, @P.z);
float mask = volumesample(1, 'mask', local_pos);
@Cd = set(0,0,mask);
f@masked = mask;

Export a heightfield from mapbox to gaea

Reset to origin

vex

// run over a hf wrangle, with grp: @name=height
vector bbox = getbbox_min(0);
float min = bbox.y;
@height -= min;

vex

//Run over detail
vector size = getbbox_size(0);
f@height_factor = size.y/(size.x/2);

as expression on a Heightfield output node/To Range, high bound :

detail("../set_detail/", "height_factor", 0)

This is used to export the heightmap texture to gaea with the correct scaling factor