When it comes to creating skins in any game, one of the most used and known visual enhancements is Normal Mapping, Normal Maps are a technique used for faking the lighting of bumps and dents, When creating these for Garry's Mod (or any other source game) many people tend to use VTFEdit to generate their own normal maps, in the past, i've used this technique and it has never given me the results i've been looking for, after a while, i managed to find a way to create better versions of these via Blender, this tutorial will show you how to create your own in Blender.
For example, The image on the left has a Normal map whilst the image on the right Does not have a Normal Map
The only programs you will need for this tutorial is Blender and VTFEdit.
To make this tutorial easier for everyone i've already made a template for people to use, you can find this Here
It would be worth mentioning that Blender doesn't like .TGA files, it would be recommended to create a separate .PNG version of your skin to use in Blender
Once you have downloaded the .blend file you can go ahead and open it in Blender via File-Open and find the location of the downloaded file, once you have done that you should see this:
For the time being, we don't need to take notice of the right window, that well come later on, Now you have this open you can go ahead and open the file you want to create a normal map from, you can do this on the right side where it says Image like so:
For this tutorial I'll be using the Symbiote gloves and a example.
Once you have opened your skin that you want to create a Normal Map with you should see this:
as you can see, the areas marked with white in the image on the right side of the screen are protruding from the plane.
Next you want to head over to the Modifiers tab which can be found on the right side here:
Once you have that open you can go ahead and change the Strength of the Displacement to what suits you or your skin (a strength value of 0.050 to 0.500 is preferred)
As you can see, i have reduced the strength to 0.100 and the bumps are more shallow compared to 0.500.
Note: this may also take time depending on your current hardware
Now that we have found our preferred Strength we can go ahead and click Apply on the modifiers.
Make sure you follow this image correctly or else you WILL encounter problems in the future
This may also take a small amount of time depending on your hardware
Now that we have done that it's time to bake our normal map, Head over to the right window and click on New
Once you have done that you should see a new window show up up, just follow this Guide here:
And click OK
After that you should see the right window turns black, that's fine, just Zoom out of it until you see the entire square.
Now we have to give the Left window a material, Head over to this this tab and click New:
Once you have done that you should have new options appear underneath this, Head to Surface and then head to color, and click on the dot on the right and head to Image Texture like so:
Now that you have done this the options for the color setting would have changed, simply click on the file icon next to Open and select your black image called Normal Map:
Now that you have done that you can head over to the Camera icon in the settings bar and scroll at the way down to where it says Bake and expand it:
Once you have done that, Follow the settings on this screenshot and then click Bake:
When you click Bake, it may take a while depending on your current hardware, but when it has finished you should see a result similar to this:
If you are happy with the result you can go ahead and save this Normal Map by clicking Image and Save As Image:
It is preferred if you save it as a .PNG file, after you have done that you can go ahead and open VTFEdit and import the Normal Map file and save it as a .VTF, Whilst creating your VMT you'll most likely have to edit the "$bumpMap" (which is another name for a Normal Map) to the location of your Normal map, which should be placed in the same folder as your skin.