How to position instances of a mesh in to any format

Questions
1

how to position instances of a mesh in to any format such as having the instances on a plane and shape the instances in a hexagon

2

Your question is somewhat not clear to me. One of the possible interpretations is: how to position individual instances of a mesh, so that each instance has its own position. If this is your question, look at this example, which positions 8 instances in an octagonal formation:

https://codepen.io/boytchev/full/yLxpGBX

image

3

what i meant was how would i be able to instance grass mesh or shader with accurate positioning on a plane, similar to if i imported a house glb file and wanted grass instances around it,

this post was close by using vertex painting in blender but was not very clear on how to achieve it exactly.

4

If you plan to use MeshSurfaceSampler and you want to exclude the area where the house is, you should do this:

  • pick an attribute that keeps weights of every vertex in the mesh
  • let the sampler know what is the name of this attribute (setWeightAttribute)
  • set the weight 0 for each vertex under the house , and 1 to each vertex around the house
  • build an internal “map” of allowed and forbidden areas (build)
  • and then you can pick random positions in the allowed areas (sample)

I’m afraid that I do not understand your question again. Maybe someone could be more helpful

1 Like
5

As @PavelBoytchev has mentioned you need to use the surface sampler, here’s some example code to put you in the correct direction…

sampler = new MeshSurfaceSampler( groundobj )
.setWeightAttribute( 'color' )
.build();
for ( let i = 0; i < instanceCount; i ++ ) {
  sampler.sample( position ); 
  dummy.position.copy(position) 
  InstanceMesh.setMatrixAt( i, dummy.matrix)
  InstanceMesh.instanceMatrix.needsUpdate = true;
}
6

thank you!