Combining links to related resources from multiple sources:
It’s not possible, mainly because if that was allowed the first thing people bump into is that the order in which transparent objects get renderer is incorrect.
In order to render them correctly the instances will need to be reordered every time the camera moves.
- Opacity for InstancedMesh - Questions - three.js forum
- Feature request: support InstancedMesh.setOpacityAt(index,color) · Issue #20431 · mrdoob/three.js
- BatchedMesh: add per-instance setOpacity by Kikedao · Pull Request #28151 · mrdoob/three.js
- add per-instance opacity by trusktr · Pull Request #35 · pailhead/three-instanced-mesh
- BatchedMesh set per-instance opacity - Questions - three.js forum
- Opacity attribute for instanced geometry? - Questions - three.js forum
- lume/three-instanced-mesh: A better InstancedMesh class for Three.js
- three.js - Transparency within instanced shapes - Stack Overflow