We haven’t tried this ourselves, but it’s probably possible to achieve this with custom tileset materials!
First, create a copy of MI_CesiumThreeOverlaysAndClipping. Then, switch it to the Unlit lighting mode.
Then, make a copy of the ML_CesiumGltf material, and have your new material instance use it as a base layer. Multiply the output color by a large factor (e.g., 100000) to get that bright glow. You have to do this because CesiumSunSky is a really strong light source, so the points won’t appear lit in comparison.
Finally, in the SetMaterialAttributes node, you will have to output the color in the Emissive Color attribute, instead of Base Color.
If you need it as reference, we have a general tutorial about editing tileset materials on our website: Editing Tileset Materials – Cesium.