You can change which skin is being used with the Top-Right Panel. This allows you to edit the texture file, normal map, alpha, as well as different Material properties and special effects.
Weapon Texture/Replacing Images
Press the X icon (to the right of Hyper Beast.png in this photo) to remove an Image. To replace the image, press the Open button that will appear after pressing the X. The options below this (Color/Non-Color Data, Linear, Flat, Repeat, Single Image, Vector) don't matter, so leave them be.
The Weapon Texture is the base VTF you would import into GMod
Value from 0 to 1. Set this to 0 for non-metal materials, and set this to 1 for metallic materials.
Below is an example comparing value 0 (Dielectric Plastic) to 1 (Standard Metal)
Value from 0 to 1. Controls how shiny or how dull a material will render. TIP: Metallic materials + Low Roughness + Normals = Nasty. Avoid that if you can.
Below is an example comparing value 0.2 to 0.4
Value from 0 to 1. Controls how reflective the surface is at an intense angle. Leave this at 0.5 for 99% of cases, unless you're making an incredibly dull material such as rock, which would need to be set lower.
Below is an example comparing 0 to 0.5. This wasn't in the previous version of Skin Renderer, I wish I was kidding.
Normal Map/Normal Map Strength
Normal Map- Image Input
Normal Map Strength- Value from 0 to Infinity.
Creates bumps in the surface of the weapon. If no Normal Map is loaded but the Normal Map Strength is above 0, a Normal Map will be automatically generated.
Below is an example comparing no Normal Map to the Generated Normal to the Image Input Normal
Value from 0 to 1. Changes the Normal Mapping method. 0 creates bumps in the actual material itself, whereas 1 creates a thin glossy layer over the material and applies the normal on that.
Below is an example comparing values 0 to 1, the effect is subtle on the second picture but is still there
Image Input, values under the Open tab should be ignored.
Image from black to white in certain areas, allows Image effects to be used (See below)
Note: This does not support TGA Alpha channels due to Blender limitations, so you'll have to save these separately from the TGA.
Value from 0 to Infinity.
Lights the weapon based on the Alpha Channel image. This light will also affect nearby objects. Disabled if no Alpha is detected.
Below is an example comparing values 0 to 3, under low lighting levels.
RGB Value (Click the White Box to edit)
Enable Custom Colour- 0 to 1
Changes the Base Texture's colour based on the Alpha Channel image. All other effects will still work.
Below is an example comparing disabled to enabled.