Change Material Index On a Solid Particle

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Hey @PirateJC and @JCPalmer (or anyone) … hey bro how do update the material index on and multi material solid particle system.

If i change the sps.particle[i].materialIndex … is has NO visible change.

Are you suppose to be able to change a particle by updating the materialIndex ???

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adding @jerome

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Found it

@Pryme8

Help me find it

ComputeSubMeshes

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For those wanting the full explanation : Solid Particle System Materials | Babylon.js Documentation

The difference with the other particle properties (positon, rotation, etc) is that setParticles() doesn’t compute the materials at all.
Indeed setParticles() is designed to be called each frame in the render loop and to make sure to keep the garbage collector activity to its minimum by allocating nothing.
Applying the changes of materialIndex values requires to sort again all the particles, to recompute the whole SPS geometry and moreover to recreate new SubMesh objects from the SPS mesh.
Therefore a dedicated method is provided sps.computeSubMeshes() . This method is to be called manually after each change of particle materialIndex values for them to be taken in account at once.
Like setMultiMaterials() , it’s probably not a good idea to call it each frame in the render loop.

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