If you want to know more about porting models with Blender, I'd suggest to take a look for these useful guides on the Internet.

7 Different Kinds Of Smoke - Entire process of porting models to SS fusion, this also applies for SS HD, BFE and 4.

This video is perfect if you dont know the ins and outs for creating models for Serious Sam and also covers the basic proccess of using Blender, perfect for beginners! (I'd like to tell you to check a guide for weight painting in Blender after you have seen this)


Pan's guide for the extra nuisances in SS4
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2434203310
Dont forget to check Pan's guide for checking the extra new steps for creating models in SS4! THIS IS IMPORTANT!!

Old but gold - noam 2000's playermodel guide
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=410715711
The original guide for creating playermodels for Serious Sam 3, this guide is quite old but also has some useful steps that you'll want to know.

The bones in white are not necessary at all, and I think the eyes bones interfere with the models face than anything else. If you want to give your character facial expressions, just rename your shape keys as the same name that SS4 models use, there is a small list of useful shape keys for your character down below.

I'd like to implore anybody looking for sanity to leave weight painting the fingers as the last step, since these are pain.



For creating frist person arms viewmodel, all you need is to do the same process, from the Upperarm to all the way down to the fingers. You can copy and butcher the arms of your playermodel to create the frist person viewmodel easily.

Character skeleton
https://files.catbox.moe/uejswy.fbx

Frist person arms
https://files.catbox.moe/mn5oqq.fbx

If you want to add facial expressions to your model, you need to create shape keys and name them in a way that Serious Sam 4 can recognize.



I dont know how to create shape keys in Blender since im not a modeller, but my method is to use a model that already has shape keys and then rename them accordingly so once I export the finished model to Serious Sam the engine can render shape keys succesfully.

So, rename or create shape keys and name them just like on the image shown, and then export the model as usual, remember to export the model while having the BASE shape key selected (aka Basis).

You can check if your model has shape keys in Serious Sam Editor via checking the animation list.

Here's a useful template for creating female characters.
If you want to create a male character you might want to expand the image a little more.