Using 'color weighted attribute for MeshSurfaceSampler

Questions
1

Hi, I am trying to build some grass patches with MeshSurfaceSampler with InstancedMesh.

The patch surface i am sampling is a mesh with a merged geometry of a circles (with random thetaStart) and other shapes.
The patch is also mapped with a gradient texture

      /// merge all surface geometries created in the loop for all images within the room
      var merged_surface_geom = mergeBufferGeometries(surface_geom_array, false)
      var grass_surface_mat = new THREE.MeshBasicMaterial({
        color: 0xffffff,
        side: 1,
        opacity: 1,
        map: colorTexture,
        alphaMap: colorTexture,
        alphaTest: 0.5,
        transparent: true,
      })
      var grass_surface_mesh = new THREE.Mesh(
        merged_surface_geom,
        grass_surface_mat
      )
      grass_surface_mesh.visible = true
      // add to subparent
      single_world_grp.add(grass_surface_mesh)

      var sampler = new MeshSurfaceSampler(grass_surface_mesh)
        .setWeightAttribute('color')
        .build()

With the summarized code above, i managed to create this. I am trying to make the grass grow more in the areas where there are colors (from the mapped texture?)

Screen Shot 2022-07-30 at 17.14.55
Screen Shot 2022-07-30 at 17.14.551398×896 78.4 KB

But as you can see, the grass seems to grow pretty evenly / randomly . How do i use ‘color’ weighted attribute from MeshSurfaceSampler to achieve the weighted sampling on colors?

2

Hi!
Have a look at this for some ideas:

1 Like
3

this was of great help! thanks

one strange this is that the weighted distribution only works sometimes on refresh and not working on other times.