Baseline requirement of a PBR-compliant game ready model/texture?

[Abhijeet]

hello guys ,
i need some help.

i have been sculpting in zbrush for some time , now i am looking for job in game industry.
i am a fresher.

Now when i applied in some gaming companies , they told me to share my low-polygon models carrying in-game textures like color map , normal map , roughness map, etc. So i extracted all maps from zbrush and the low poly model and gave it to them .

But then they told me that the file does not meet our baseline requirement of a PBR-compliant game ready model/texture.
I don’t know what it means , i don’t have any idea how any zbrush file is used in games.small_orange_diamond:o

So please someone help me and guide me how to send my file and maps to any company.

[Abhijeet]

Attachments

[Cryrid]

PBR:

PBR stands for physically based rendering.

• https://marmoset.co/posts/basic-theory-of-physically-based-rendering/
• https://marmoset.co/posts/physically-based-rendering-and-you-can-too/

Long story short, you’re going to need several different types of texture maps in order to accurately describe any given material (albedo, roughness, reflectivity, ambient occlusion, normal map, and potentially others depending on the type of shader being used by the game engine).

The reality is that Zbrush isn’t going to be a good choice for painting a model meant for PBR rendering. One of the reasons zbrush is so easily able to handle the massive amounts of polygons per model that it can in the first place is because it doesn’t render models with the same kind of shaders that game engines and other 3d programs use. It doesn’t use lights and cameras and surface shaders… instead it fakes its materials through matcaps and images of spheres. Polypaint might be able to convey the data of one RBG texture map, but the shaders for PBR game models will demand several different texture maps (a lot more channels of data) simultaneously working together to create the final result.

Substance Painter is a popular choice since it has a PBR viewport and will let you paint all of these different channels at the same time. Quixel DDO is another choice. In addition to these tools I would also recommend playing with Marmoset Toolbag, Unity, or the Unreal 4 engine so that you can get a better idea what kind of texture maps PBR shaders will look for and how different values will change the results.

Model:

Finally, you’re also going to want to research game topology as well. Currently, the wireframe on the face that you showed looks like a basic grid with no proper edgeflow around any key features of the face. Compare it to examples here, and how these wireframes form edge-loops around the eyes, lips, and nasialabial region. The body is going to be similar in that you’ll want an edgeflow that can isolate and define important muscle groups while providing topology that can deform nicely during animation. It’s going to help if you have access to a program like Blender, Maya, Max, etc where you can rig and animate models. You don’t have to dive too deep into those fields, but having at least some basic experience with that will give you a better understanding of how a model’s topology affects its deformation.

Workflows can change depending on your pipeline and if you’re using a basemesh, but generally you’ll want to:

1. Sculpt the highpoly model with your detail. Good topology at this stage can still be important for sculpting, but you have a lot more freedom since you have millions of polygons to work with unlike game models. Save the sculpt somewhere (obj or fbx).
2. Retopologize the sculpt. Basically create a second model with the exact same proportions, but focus on clean topology for animation such as in the examples above. For a good game model you will want to look into manual retopology. There are different tools that can help you with this, but basically it consists of loading the highpoly model as a guideline and then drawing the new model's wireframe on top of it.
3. This lowpoly game model will also need UVs. When the model is finished and UV'd, save it out as an obj or fbx file as well.
4. Load both models into a baking program such as Substance Painter, Marmoset Toolbag, or xnormal in order to bake out some starting data maps (normal, curvature, ambient occlusion, etc).
5. From there you can load the lowpoly model and all those baked maps into a painting program like Substance Painter in order to begin painting the texture maps that the game engine will use.

It's a lot of information to take in, but there's a reason it can take years to get the knowledge and experience required to enter the field. I would start looking for courses and training videos that will go over the process of creating a Game Ready model. Specifically find one that covers retopology ([like this](https://www.pluralsight.com/courses/game-characters-maya-zbrush-457)) so that you'll know how to create a game ready model from a zbrush sculpt, and then from there look into videos covering Substance Painter or whatever so that you can learn more about creating PBR textures.

[Abhijeet]

Thanks for the reply .

As you told me i have to retopolize my model , so after seeing some examples now i am working on the topology of my low poly model .

Now i have some doubts regarding the texture ,

1. i will bake normal map using Xnormal. will it be good and ready for game ?
2. can i use the texture from polypaint from zbrush ?
3. what should be the poly count for my male character to be game ready ?

one more thing is that i am not able to understand this , i read that game engines use triangles but my model is in quads , so will it create problem ? do i have to have all triangles in my model ?

[Cryrid]

1. xnormal is a great baking program. You’ll probably want to use it to bake a few additional map types as well (such as ambient occlusion).

2. You can but I personally wouldn’t recommend it for the kind of pipeline you’re aiming for. It’s way more convenient to use a baking program that lets you use two different models (a lowpoly model with UVs for the game, and the high res sculpt). Plus with polypaint you’re limited to just RGB channels so you won’t be able to paint other maps (roughness, etc) at the same time.

3. There’s too many factors to give any single number. An RTS game with dozens or hundreds of units on screen at once seen from far away will have different requirements than a fighting game that only has to focus on two characters with a closer camera. You could be looking at 2000 triangles for some games, or upwards of 120 000 triangles for others. Just because you can go that high doesn’t mean you should though - you’ll want to make sure you’re using those polygons efficiently at the end of the day.

4. Quads won’t create a problem. Each quad is always (secretly) two triangles as far as a renderer goes. Computers do this in part because they are easier to calculate (a triangle will always be planar). But with that in mind, you’re going to want to work mostly with quads as these will make it easier for you (and others) to work with. For example you’ll be able to select edgeloops thanks to quads. Don’t worry about working 100% exclusively with quads however - some triangles here and there are perfectly fine and will even be vital for really lowpoly models.

I’m not sure what other programs you have access to, but if you have something like Maya then I would at least lock the vertex normals down prior to exporting (and possibly even triangulate the mesh at this point), since these could otherwise shift around depending on how the baker and game engine choose to triangulate. This entryhas some more information.