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
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. 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
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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).