How to Change The Default Shader of the elusive "None (Material)" given to imported FBX files

[Bmco]

I have a ~200 imported models (as fbx from Blender). Each one has a standard base texture and normal map.

By default, Unity appears to have a placeholder material called “None” for each imported fbx, but it is not shown as a separate material (in the file explorer). I’m using URP and the Shader is auto-set to URP/Lit.

Now, I have a Shader Graph version of URP/Lit, and I’ve added some additional effects I can turn on/off.

I want these effects to be available to all my imported models.

All I would need to do is change the Shader of this elusive “None (Material)”. However, I’m worried there’s no quick fix…

What is the best way to handle this given that ALL PREFABS ARE GENERATED AT RUNTIME?

1. The Easiest option would be auto-setting to my custom shader instead of URP/Lit. Is there a setting somewhere to do this?

2. Should I create just one material with no textures and set the textures and FX settings at runtime? The drawback here is that the prefab’s textures will be blank for editor/prefab editor use.

3. Should Each Imported Model Have its own dedicated material?

[Kurt-Dekker]

@Bmco

ALL PREFABS ARE GENERATED AT RUNTIME?

Prefabs cannot be generated at runtime. Prefabs exist only in editor and are created only by tooling in the UnityEditor namespace, which never goes into a final build, ever.

@Bmco

By default, Unity appears to have a placeholder material called “None” for each imported fbx

You can disable this by not importing materials at all. This lets you create and apply any material you like to any geometry.

Here are my notes on using Blender3D with Unity3D:

---

When I work in Blender3D for Unity3D use, I follow these organizational rules:

• use Empty Blender Objects as folders: they come out as an extra GameObject

• ALWAYS parent everything to a single Empty, even a single object

• ALWAYS apply all Scales and Rotations on every Transform throughout your hierarchy.

• put as few objects in a given .blend file as possible, combining them in Unity into a prefab

• REMOVE unnecessary items (Light, Camera, etc.)

• use good names for your Blender3D objects and NEVER RENAME them after Unity sees them

• don’t even think about final Materials or Textures in Blender. Set the mesh to use N different materials, but always set up the materials within Unity and disregard what gets imported.

---

Costs of using Blender files directly vs exporting to FBX:

Any cons to keeping models as blend files?

I can answer your question precisely. I freakin’ HATE fiddling and clicking with FBX export, etc. Keeping files ONLY as Blender files is awesome, one of the most endearing simplifying things about Unity with Blender. But as you intuit above, there are potential hidden costs. Here are the two major costs. Cost #1: every place you wish to build this will REQUIRE Blender be installed. Your computer? Fine! Install it! Your friend’s computer? Eh, maybe you can entice him into installing it. Now… U…

Unity imports Blender3D objects as FBX via a little Python script:

From Blender to Unity problem

Often distortions can come as a result of modifiers and/or scales existing through your transform hierarchy. In Object mode in Blender, always have your rotations set as (0,0,0) and your scales set as (1,1,1) otherwise you will have issues. You can apply those transforms in Blender. Unity runs this script to import your Blender files via transient FBX export: ./Hub/Editor/2020.1.5f1/Unity.app/Contents/Tools/Unity-BlenderToFBX.py ./Hub/Editor/2020.2.1f1/Unity.app/Contents/Tools/Unity-BlenderToF…

The Python script that Unity uses (substitute your Unity version number or search) to import:

./Hub/Editor/2020.2.1f1/Unity.app/Contents/Tools/Unity-BlenderToFBX.py

More on fixing it:

All my mesh folder content is gone

Check your recycled bin and see if anything is retrievable. I’m sorry you’ve had this issue. Please consider using source control in order to guard and protect your hard-earned work. Personally I use git because it is free and there are tons of tutorials out there to help you set it up. Here’s how I use git in one of my games, Jetpack Kurt: Using fine-grained source control as you work to refine your engineering: Share/Sharing source code between projects: Setting up the right .gitig…

Blender3D objects used as trees / detail in Unity3D terrain (See the second half of this response)

Terrain Editor Adds The Trees in Wrong Rotation (Custom Trees Made With Blender)

This might be because your scene includes the default camera and lights. Unity started importing those with its default Blender import script starting sometime in Unity2019 and it will break a lot of prefabs. You can either a) remove the Camera and Light and everything except the LOD group objects (properly named), or you can modify the Blender import script embedded in Unity. This means you would need to re-modify it every time you switched to a new version of Unity, but I was lazy and I do t…

All components lost when changing parent in Blender

NEVER rename items in Blender after you have imported into Unity, because then Unity imports them as though they were new GameObjects. That’s how the mapping works if you look in the .meta file associated with your Blender file. It is done by name. I would also NEVER reparent them because of the root (-90,0,0) rotation issue when going from Blender’s right-hand system to Unity’s left-hand system. Reparenting potentially moves an object in or out of the guard area for this rotation. The best w…

Probuilder and Probuilderize and Blender:

ProBuilder vs Blender

This is what you need, but it’s not a free-back-and-forth-all-day-long process. You want to be very intentional and parsimonious about how many times you go back and forth because there’s a LOT of room for error. When you drop a Blender file in, Unity has Blender run a Python export script, then imports the resulting temporary FBX file, which you don’t ever see in the filesystem. When you drop that (or any model file) into your scene, it makes a GameObject, gives it a MeshFilter and MeshRend…

Some more potentially-useful info:

Orientation problem

what are you using for your fbx, export settings in blender, and what are you using for import in unity? This is what i use in blender, you want to set your Up axis and Forward not to what Unity uses for those, but to how your axis are being used in blender. Also make sure Apply Transform is enabled. [8037734--1036694--upload_2022-4-11_9-51-35.png] in Unity i have this. [8037734--1036700--upload_2022-4-11_9-54-11.png]

Updating Blender files without breaking your prefabs:

Is it Possible to Edit a Prefab in Blender

Yes ^ ^ ^ the above… but there are limitations. Generally you cannot ADD new items, only change existing items. Here’s why: Any arbitrary FBX model (including Blender files automatically imported as FBX files in Unity) is a collection of things: each object becomes a GameObject each might have a mesh each might generate / use materials there are parent/child relations between objects The collective bunch of things is imported and given Unity-side names (called GUIDs) based on their Blender …

[Bmco]

@Kurt-Dekker

Prefabs cannot be generated at runtime.

What’s the proper way to phrase it, instantiated at runtime? What I meant was these meshes do not exist in the scene beforehand.

Thank you for the in-depth response. From here, I’m just wondering if I have to create a bunch of materials to replace the default “None” material since I only need to change the shader.

[Kurt-Dekker]

@Bmco

instantiated at runtime?

Procedural generation… yes, a subject near and dear to my heart.

It’s all about WHAT you instantiate. If you are only instantiating models you also need to do lots of other things like putting colliders or scripts or materials, etc. Yes, you CAN write code for that stuff but it’s probably the hardest most annoying code to write ever.

Instead, make prefabs in the editor, save them and instantiate and customize those prefabs at runtime. That lets you “capture” a bunch of work value into the prefabs, then instantiate and customize them.

If you want random samples of various procgen, you’re welcome to look around my MakeGeo project.

MakeGeo is presently hosted at these locations:

https://bitbucket.org/kurtdekker/makegeo

GitHub - kurtdekker/makegeo: Make Geometry - Procedural Unity3D Geometry

Kurt Dekker / makegeo · GitLab

makegeo

[Bmco]

Kurt,

Thank you once again for the extra info/context. However, in order to close out this topic, what should I do with my material situation? Make a new material for each prefab so I can set the Shader?

I’m assuming I screwed myself with the None Material when I first imported the fbx’s.

[Kurt-Dekker]

Before you thunder too much further ahead, review how Materials are instanced for things in scene.

By default if you instantiate a prefab, it uses the Materials originally connected to it.

If you need to modify the Materials at runtime, how you get that material from the renderer determines if it will be the one on disk (which you should NOT modify at runtime), or a copy.

When you read a Material from a Renderer.material, Unity makes a copy of it when you modify it, making it necessary to assign it back.

If you use the Renderer.sharedMaterial field it does not make a copy.

You can always make fresh copies of your Materials before you modify them.

Play with it antagonistically a bit, you’ll soon see how it works.