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I am drawing up a small scale island about 30mm in diameter which will be 3D printed in resin as part of a diarama scene. The island needs to be covered in grass. I am struggling to get achieve grass, I have tried using poke but not giving a very natural look. I tried using the particle system with hair but cant get the rotation to work to make the hair go straight up....?

Can anyone help? Thanks.

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You can draw geometry on other geometry by mixing Weight Painting and Geometry Nodes.

Draw weights on your geometry.

Island-like geometry with weight paints leaving a line in the middle

Then create a Geometry node setup that looks something like this:

Simple geometry node setup that distributes points on geometry and instances a cone per point

The Name on the Named Attribute-node is the same name that your weight paint vertex group name have. The cone can be any geometry that looks like grass. It is important that you have a Realize Instances-node as it will not export the geometry for 3D printing otherwise.

Cones distributed on island-like geometry

If you want the grass to extend out from the geometry rather than all pointing upwards you can align the rotation using the following modification:

Aligning the cones to the smooth normal

The Set Shade Smooth-node is setting making it so that the normals we align the cones to are smoother than they would be without it.

Cones distributed on island-like geometry align to smooth normals

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  • $\begingroup$ Thank you, this looks exactly like what I need. I have never used that panel before, I have tried recreating what you have but how do I add the Named Attribute & Cone, when I try it comes in looking different? PS. Is there no easy way to just make the particle-system-hair rotate upwards? $\endgroup$ Commented Mar 21 at 21:58
  • $\begingroup$ The screenshots come from Blender 4.0.2. I add the nodes by pressing shift+A and typing (searching) the node name. The numbers in the inputs on the nodes where more or less selected at random. I have no experience with the particle system. Perhaps someone else can write an answer that uses it. $\endgroup$ Commented Mar 21 at 22:15
  • $\begingroup$ Thanks, still cant add the name attribute box...? I have this setup on the moment but not working correctly. imgur.com/a/mQbR8Nm $\endgroup$ Commented Mar 21 at 22:25
  • $\begingroup$ The Geometry Node-modifier needs to go on the "island". No idea why the Named Attribute-node isn't popping up. In the Geometry Node panel menu it should be under "Add" -> "Geometry" -> "Read" -> "Named Attribute". $\endgroup$ Commented Mar 21 at 22:33
  • $\begingroup$ These are the options i have in Add - Geometry imgur.com/undefined $\endgroup$ Commented Mar 21 at 22:43

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