SL40 UBGL Standalone Grenade Launcher

SL40 Standalone UBGL Vray Render

I stumbled across news of a standalone chassis being developed for the SL40 Under Barrel Grenade Launcher and decided that I would whip up a 3D version.


Developed by Lithgow Arms for the Australian Defence Force, the standalone chassis for the Steyr SL40 Grenade Launcher allows the launcher to be used on its own without the need to be attached to a rifle.


I used a Physically Based Rendering workflow as always with a low and high poly model producing bakes and textures in Substance Painter and then exporting to both Marmoset Toolbag and Unreal Engine for renders.

SL40 wireframe
SL40 with normal maps
SL40 textured


17963 Tris Total
5109 Launcher (2K textures)
8140 Chassis (4K textures)
4714 Sight Assembly (2K textures)

Reflex sight seen in Marmoset Toolbag


I enjoyed finding ways to get the red dot reticle and iridescent glass working in Unreal Engine and Marmoset Toolbag as both required different approaches. I used non lit geometry ahead of the glass to hide the reticle geometry and add the parallax effect to the sight for Toolbag, and BumpOffset to achieve a similar effect in Unreal Engine.

Iridescent colouring on the glass seen in Marmoset Toolbag

For the rainbow effect on the reflex sight, I used the Newton Rings secondary reflection in Marmoset Toolbag, while in Unreal Engine I combined a thin film effect iridescent shader on the colour channel with

Optional glare reducer fitted to the reflex sight
SL40 UBGL Rendered in Unreal Engine
SL40 UBGL Rendered in Unreal Engine

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