You'll need to make sure your video settings in the game have all the special effects turned on. You'll need at least realtime lighting with at least 1 light, shader settings on high, stuff like that.
I think that special effects turned on (scrin 1). But effect did not exist.
Any way, I decided to leave as it is. I added a little more color, so that weapon are not merged into a single gray spot. I am quite happy with the result of my work
. New weapon works fine and looking good. If anyone is interested I can put the result as a mod for the game. And thank you very much for your help!
PS: Of course, I'd love to see this weapon in new game version
You can try it now. In archiv file you can find model of weapon and ammunition in .MD2 format with textures and configuration files for the game (weapons_human.ufo, researched_list.ufo, research.ufo).