Hi have a nice day , i try to make a simplex noise to gltf model (create it in blender) , The first problem is i cannot access to vertices so i found a way, no error but nothing happen that’s my code var k = 1.9; let update = () => { var time = performance.now() * 0.0009; var vertex = ne…

[image] lolia: for (var i = 0; i < positionAttribute.count; i++) { vertex.fromBufferAttribute(positionAttribute, i); let p = vertex; p.normalize().multiplyScalar(1 + 0.09 * simplex.noise3D(p.x * k, p.y * k, p.z * k + time)); } This part needs one more line at the end: po…

Not sure, but shouldn’t you set the changed values back to the buffer? mesh.geometry.attributes.position.setXYZ(i, p.x, p.y, p.z);

Hi! [image] lolia: mesh.geometry.normalsNeedUpdate = true; mesh.geometry.verticesNeedUpdate = true; Try to use this instead: mesh.geometry.attributes.position.needsUpdate = true; mesh.geometry.attributes.normal.needsUpdate = true;

I try that but not working Unfortunately

Without a glitch it is difficult to see what might be wrong. I use something similar on a gltf model, so it can work. Do you perhaps have multiple meshes, and only address one (just guessing now)?.

[image] awonnink: guessing No i use just one mesh

thank you for replay but when i add this the mesh disappear for (var i = 0; i < positionAttribute.count; i++) { vertex.fromBufferAttribute(positionAttribute, i); let p = vertex; p.normalize().multiplyScalar(1 + 0.09 * simplex.noise3D(p.x * k, p.y * k, p.z * k + time)); po…

[image] lolia: fromBufferAttribute Can it be that you should not use i++, but every third position i=i+3? Buffer attributes have their x, y z positions in sequences (see Three.js Custom BufferGeometry (threejsfundamentals.org) )

[image] awonnink: Can it be that you should not use i++, but every third position i=i+3? .fromBufferAttribute() internally uses .getX() (and .getY(), .getZ()) method, that takes in count attribute’s item size.

[image] lolia: mesh.geometry.normalsNeedUpdate = true; mesh.geometry.verticesNeedUpdate = true; These properties are useless, if you use a buffer geometry. With that type of geometry you have to use those ones, that applied to geometry’s attributes: [image] prisoner849: mesh.geo…

Create a simplex noise for gltf model

Questions

prisoner849 May 10, 2021, 1:43pm 3

Hi!

Try to use this instead:

mesh.geometry.attributes.position.needsUpdate = true;
mesh.geometry.attributes.normal.needsUpdate = true;

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Create a simplex noise for gltf model

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