Check if Material of a gameObject == a material variable (instance)?

Use if (go.renderer.sharedMaterial == m). Accessing renderer.material creates an instance so it's not useful for this.

You should explain more of what you are trying to do. For me, it seems like you are trying to check if GO object has the same material with M material? To compare a material to a game object, you must use gameobjectName.renderer.material. Code is below.

 public Material m;
 
 bool hasThesameMaterial(GameObject GO){
   if(GO.renderer.material==m){  //checks if they are the same material
    return true;  //returns true if the same material.
   }else{
    return false; //returns false if different material
 }
 }

To call this function, you do

 GameObject myobject; //the object you want to check if the material is the same with 'm'
 
 if(hasThesameMaterial(myobject)){
 //it has the same material
 }else{
 //it DOESNT have the same material
 }

EDIT 1:

Then in the script, I have this function to check and see if the gameobject sent in as a parameter is using one of those 4 materials, and if so, which one (just a long if-else chain)

 public Material m1;
  public Material m2;
  public Material m3;
  public Material m4;
 
     string hasAnyOfTheMaterials(GameObject GO){
    if(GO.GetComponent<MeshRenderer>()){ //Get Mesh Component
   
       if(GO.renderer.sharedMaterial==m1){  //checks if it has material 1 material
        return "m1";  
       }
       else if(GO.renderer.sharedMaterial==m2){    //checks if it has material 2 material
        return "m2";  
       }
       else if(GO.renderer.sharedMaterial==m3){    //checks if it has material 3 material
        return "m3";  
       }
      else if(GO.renderer.sharedMaterial==m4){    //checks if it has material 4 material
        return "m4";  
       }
       else{
       return "none";   //it has none of the materials
       }
     }
 }else{
 Debug.Log("No Mesh Component Found");
 }

To call the function

 GameObject myobject; //the object you want to check if it has the same material.
 if(hasAnyOfTheMaterials(myobject)=="none"){
 Debug.Log("it has none of these materials");
 }

You can also do this.

 string currentMaterial = hasAnyOfTheMaterials(myobject);
 Debug.Log("Game object's material is "+currentMaterial);

What if you want to know the ACTUAL name of the material. The name of given to the material?

Replace

 return "m1";, return "m2";, return "m3";, and return "m4";  

with

 return GO.renderer.sharedMaterial.name;

It will return the exact name the material is using. Leave "none" alone so that you can use it to determine which if the material it is using is not one of those 4 materials. If you want it to return the name of the material when it is none of those 4 materials, then replace

  return "none";

with

  return GO.renderer.sharedMaterial.name;

You can also replace

 return "none";

with

  return null;

so now you can do

 if(!hasAnyOfTheMaterials(myobject)){
 //It doesn't have any of the materials
 }else if(hasAnyOfTheMaterials(myobject)=="m1"){
  //It has Material 1
 }.................... so on

NOTE: When you use renderer.material, it creates a new instance. With renderer.sharedMaterial, it accesses the main material. Even when you read a material with renderer.material, it creates a new instance. When you modify a material's color, texture or other of its properties with renderer.material, it creates a new instance. So use renderer.sharedMaterial when you want to change a material, read or compare material value. I forgot to say that in the beginning.

And the most important change I made here is get the MeshRenderer Component "GO.GetComponent()". That might help. If not, post your code, post what you have now and I will replicate the problem on my side.

EDIT 2:

  It showed "your material is marker-hex-green (Instance) (UnityEngine.Material)". Note that marker-hex-green is the material i dragged to landingHexMat in the inspector. (it's actually two underscores, not hyphens, but the forums have weird formatting for underscores..)

You are correct. Unity doesn't like the underscores and changes it to hyphens. It is not suppose to have 'Instance' in the name. Like I said before, Instance means that that you used something like

 n.gameObject.renderer.Material....

instead of

 n.gameObject.renderer.sharedMaterial....

in your code. Check carefully in all your C# code files.

UnityEngine.Material will normally be there if you use gameObject.renderer.sharedMaterial.

To remove (UnityEngine.Material) from the name in Debug.Log(), use

  Debug.Log("your material is " + n.gameObject.renderer.sharedMaterial.**name**);

instead of

 Debug.Log("your material is " + n.gameObject.renderer.sharedMaterial);

The variable "name" will actually return the name of the object's material.

You need to change your naming Convention

From 50 Tips For Working with unity Use Pascal case, like this: ComplicatedVerySpecificObject. Do not use spaces, underscores, or hyphens

I think that this applies to File Naming too as Unity replaces underscores with hyphens.

So your "marker-hex-green" variable should be named something like markerHexGreen or markerHexGreenMat. Do the same for other Materials. The Mat reminds you that this is a Material.

After doing these above, run it and see if Instance is still showing. If yes, then you must chose one of the following temporary ways to fix it for now and look for a better way after.

Method 1: Create a public GameObject then pass the GameObject to the function. Remove

 gameObject

from

 n.gameObject.renderer.sharedMaterial == attackHexMat

Below is what you are suppose to have. Make sure to assign an object to the GameObject through the Editor.

 public GameObject myColorObject;
 
 public hexMats getNodeMatEnum(GameObject n)
 {
 if (n.GetComponent<MeshRenderer>())
 {
 if (n.renderer.sharedMaterial == defaultHexMat)
 return hexMats.defaultt;
 else if (n.renderer.sharedMaterial == landingHexMat)
 return hexMats.landing;
 else if (n.renderer.sharedMaterial == moveHexMat)
 return hexMats.move;
 else if (n.renderer.sharedMaterial == attackHexMat)
 return hexMats.attack;
 else
 {
 Debug.Log("Found the mesh component, but did not compare to any of the 4 mats. Returning default");
 Debug.Log("your material is " + n.gameObject.renderer.sharedMaterial);
 return hexMats.defaultt;
 }
 }
 else
 {
 Debug.Log("No Mesh Component Found! Returning default");
 return hexMats.defaultt;
 }
 }

The "Instance" word should now disappear. If true, then the program should work. If not, then use Method 2.

Method 2: Revert back to the code you had before you performed Method 1. The "Instance" in the material name is probably the problem. Since the word "(Instance)" appears next to the material name but not before it. You can use string manipulating to counter it. Below is your code.

 string whatToUse = "";
 
 public enum hexMats { defaultt = 0, landing = 1, move = 2, attack = 3 };
 public Material defaultHexMat; //dragged the white material to this in the inspector
 public Material landingHexMat; //dragged the green material to this in the inspector
 public Material moveHexMat; //dragged the blue material to this in the inspector
 public Material attackHexMat; //dragged the orange material to this in the inspector
 
 
 public hexMats getNodeMatEnum(TileNode n)
     {
         if (n.gameObject.GetComponent<MeshRenderer>())
         {
 
             //Call Function and See if it contains the word '(Instance)'
     if(containsInstance(n.gameObject.renderer.sharedMaterial.ToString())){
                 //It has '(Instance in the name)'
                 //Let's modify Our name
                 whatToUse = " (Instance) (UnityEngine.Material)";
     }else{
                 whatToUse = " (UnityEngine.Material)";
             }
 
 if (n.gameObject.renderer.sharedMaterial.ToString() == defaultHexMat.name+whatToUse)
                 return hexMats.defaultt;
 else if (n.gameObject.renderer.sharedMaterial.ToString() == landingHexMat.name+whatToUse)
                 return hexMats.landing;
 else if (n.gameObject.renderer.sharedMaterial.ToString() == moveHexMat.name+whatToUse)
                 return hexMats.move;
 else if (n.gameObject.renderer.sharedMaterial.ToString() == attackHexMat.name+whatToUse)
                 return hexMats.attack;
 else
             {
 Debug.Log("Found the mesh component, but did not compare to any of the 4 mats. Returning default");
 Debug.Log("your material is " + n.gameObject.renderer.sharedMaterial.name);
                 return hexMats.defaultt;
             }
         }
         else
         {
             Debug.Log("No Mesh Component Found! Returning default");
             return hexMats.defaultt;
         }
     }
 
     //Important Function
 //Checks if the word contains an instance or not
     bool containsInstance(string materialName){
         if(materialName.Contains(" (Instance) ")){
             return true;
         }else{
             return false;
         }
     }

That's it. It should work weather there is an Instance or Not.

Logic Behind Method 2:

 Two possible names returned by Unity during run time
 marker-hex-blue (UnityEngine.Material) = GO.renderer.sharedMaterial
 marker-hex-blue (Instance) (UnityEngine.Material) = GO.renderer.sharedMaterial
 We decide which one of these below to use for comparing depending on the value in     the  code above.

 marker-hex-blue (UnityEngine.Material) = m1 
 marker-hex-blue     =  m1.name 

 if go.renderer.sharedMaterial contains Instance
   add space at the end then add '(Instance)' at the end of each all material variable name followed by space then '(UnityEngine.Material)'
  else
   only add space followed by '(UnityEngine.Material)' at the end of all material variable name.
 
 //Remember we are not really modifying the name, we are concatenating it temporary and then comparing it.
   To really modify the name of the variable, we would do m1.name = "modified";
    But we never should do that and that's not what we are doing. It should now work. 

NOTE: I added a Zipped File I used for debugging and the fixing the '(Instance)' problem. You can download to see a working example.

Phew. That took long.

link text