This tutorial is for v1.1.1 of the SMPC Modding Tool, and V1.0-beta4 of SpiderTex. This will be continually updated as new versions of these tools release.
You will need:
As a precaution, open the game at least once before modding.
First thing's first, open the SMPC Modding Tool. It'll ask you to set your Asset Archive Folder. Navigate to the asset_archive folder in your game's install folder (...\STEAM\steamapps\common\Marvel's Spider-Man Remastered\asset_archive) and click save, you'll never have to do this again.
If you're just trying to install a mod you've downloaded, stop right here, and go to the "Installing/Uninstalling a Mod" section.
Now you'll see a bunch of items on the left, named g00s000, g00s001, etc. These are the game files, broken up into individual sections. For the purposes of this, we're going to be focusing on suit textures, because that's what I'm most familiar with, and understanding how suit textures work in the game will help you understand how other files work.
Double clicking a g00s will open up the tree, and allow you to explore. For the purposes of this, open g00s000 > characters > hero > hero-spiderman and click on textures to open the textures on the right hand side.
Here you can see the textures that make up the Advanced Suit. They're all "Texture" assets, meaning they're graphics that can be edited. We're going to stay away from models and animations for this tutorial.
There are a lot of files here, and here's generally what they are/mean:
There's more, but they're not necessary for now.
You can export the texture by right clicking it, and clicking Extract asset... -- I'd recommend making a folder in the asset_archive folder called Modded Assets and store them there, just to make it easier to use the tool.
When you export a texture, you'll find that it is a .texture file, and isn't usable. This is where SpiderTex comes in. All you have to do is take the file, and drag it onto the SpiderTex.exe and it'll convert it into a .png for you. Try it out!
...it didn't work?
That's because this isn't the only version of those files that exist. Right now we're looking at the lower quality versions of the textures. All low quality textures will be in either g00s000 or g00s001.
On the left, go to g00s014 > characters > hero > hero_spiderman > textures. You'll notice that many of the same files are here, though with larger sizes. These are the HD files, SpiderTex is built in a way to only allow you to export and reimport images if you have both to make sure you don't accidentally only do one (the game will be very strange if you only do one and not the other). All HD textures will be in g00s014-g00s016. You can use the search function to find what exact file you're looking for, and where it's located.
Export the same texture, and at the end before the .texture add "_hd". This is what SpiderTex needs to understand what's going on.
Drag the original .texture file onto SpiderTex (not the HD one), and you should get a .png and a metadata json file. Don't touch the metadata file, it's information SpiderTex needs to be able to convert your .png back into two .texture files, one low-res, one HD. You only need to edit one image to get both versions, isn't that great?!
You can now edit your texture to your heart's content, either a re-coloring, or a whole new suit design by editing all the various layers into a complex new design. We'll get into texture editing specifically a bit later.
Once you're done editing, you can take your .png and drag it back onto the SpiderTex.exe and it'll spit out two new .texture files with "_custom" appended to the end. These are your new texture files.
Now, go back to the files you exported before in SMPC, right click the texture, and click Replace asset in mod... and choose the new custom texture. Make sure you're putting the low-res version over the low-res version in SMPC, and same for HD. Now you can click Launch Game Modded (and select your Spider-Man PC executable) and see your new texture in game!
Once you've finished editing all your textures, you've viewed it in game and taken many photos, it's time to create the mod file. Go into SMPC, replace all of the texture files with your custom textures that you want, and go to Create Mod at the top. Here you can name it, write your name down, give it a description, and upload a 200x200 .png thumbnail. Make sure all of the files you've modified are in fact in Modified Files, and click create mod.
Then all you have to do is .zip it up, and upload it to Nexus Mods with all of your pretty photos!
Installing mods is very simple. All you have to do is open the mod manager in SMPC Tool, add your .smpcmod file, click the checkbox, and click install mods. There is also a tool that adds support for modding to Vortex, if you'd like to use that instead.
Uninstalling is equally as easy, uncheck the mod you want to uninstall and click install mods once again. You can also remove mods from the list.
Mod load order is also important, and will determine which assets are loaded first/last. The mods at the top of the list are loaded first, and will be overridden by any mods afterward. So, if you have a mod that changes the mask and the gloves on the advanced suit, and then install another mod after that one that just changes the gloves, the mask from the first mod will appear, and the gloves from the second mod will appear. This is useful for mods that include add-ons, such as optional variant textures.
There's lots of different programs / ways to edit textures. Some people using 3D software to paint onto a model, some people use photoshop to edit the files directly -- I use a combination of photoshop, inkscape, and paint.net to make my textures. There's thousands of lists, reviews, and tutorials of various image editing apps on the internet, I don't think it's necessary that I make another. I will however go a little more in depth on certain textures.
_g textures, or what I'm calling "glossy" textures can be made by taking your _c texture and lowering the transparency. If your program can do custom stuff to the curves (like with the Curves+ extension in paint.net), you can make certain colors more transparent or less, the more transparent is is the glossier it'll appear.
If you have any questions / think I got anything wrong, feel free to comment below or contact the #support or #modding channels on the Discord.