Doesn't seem to apply overrides when they are sent all at once right after PRIM_RENDER_MATERIAL . So this won't work: llSetLinkPrimitiveParamsFast(LINK_THIS, [49,0,"aa904b20-3a56-29c6-03c5-cd53c9ce3484",48,0,"",<1.000000, 1.000000, 0.000000>,<0.000000, 0.000000, 0.000000>,0.000000,<1.000000, 0.452452, 0.452452>,0.800000,0,"","",45,0,"",<1.000000, 1.000000, 0.000000>,<0.000000, 0.000000, 0.000000>,1.570800,47,0,"",<1.000000, 1.000000, 0.000000>,<0.000000, 0.000000, 0.000000>,1.570800,1.000000,0.000000,46,0,"",<1.000000, 1.000000, 0.000000>,<0.000000, 0.000000, 0.000000>,1.570800,""]); Split into two will work: llSetLinkPrimitiveParamsFast(LINK_THIS, [49,0,"aa904b20-3a56-29c6-03c5-cd53c9ce3484"]); llSetLinkPrimitiveParamsFast(LINK_THIS,[48,0,"",<1.000000, 1.000000, 0.000000>,<0.000000, 0.000000, 0.000000>,0.000000,<1.000000, 0.452452, 0.452452>,0.800000,0,"","",45,0,"",<1.000000, 1.000000, 0.000000>,<0.000000, 0.000000, 0.000000>,1.570800,47,0,"",<1.000000, 1.000000, 0.000000>,<0.000000, 0.000000, 0.000000>,1.570800,1.000000,0.000000,46,0,"",<1.000000, 1.000000, 0.000000>,<0.000000, 0.000000, 0.000000>,1.570800,""]);