Using HDR lightmap result in weird color banding and lumiance range

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10

thats just the RGBELoader source.

For anyone looking at this problem and since threejs devs always abandon threads half way (leaving devs to fend for themselves in this maze), this is how you do it

const updateLightmap = (mat, lmap, flipY, config) =>{
        lmap.flipY = flipY; // true / false
        mat.lightMap = lmap; // texture
        mat.lightMapIntensity = config?.intensity || 1;
        mat.needsUpdate = true;
}
  rgbeloader.load(`lightmap.hdr`, ( texture =>{
        updateLightmap(scn.material,  texture, false, {intensity: 1});
   }));

that should work