I'm currently trying to modify the material of a mesh via code, but I don't want it to affect all the meshes with that material.
It's basically all instances of the same mesh, and I want to change the color.

How can I do that ?

Thanks !

var material = get_surface_override_material(0)
material.albedo_color = Color(full_color.r, full_color.g,full_color.b)
set_surface_override_material(0, material)
  • xyz replied to this.
  • Loxyrak Just to clarify, how would you do a copy of the material in code ?

    var material2 = material1.duplicate()

    Loxyrak Make a copy of the material and assign that copy to the mesh.

    Just to clarify, how would you do a copy of the material in code ?

    Get surface material then instantiate it and apply it to the mesh ?

      Loxyrak To "copy", I think you need to use the duplicate() function. But I dont think its necessary... What happens if you just :

      obj1.set_surface_override_material(0, yournewmaterial)
      obj2.set_surface_override_material(0, yournewmaterial)

        Loxyrak Just to clarify, how would you do a copy of the material in code ?

        var material2 = material1.duplicate()

        IceBergyn ha, sorry, I read it wrong, you DONT want the material to be the same on your objects, in that case you need to use what xyz said, use the duplicate method !

        a year later

        Having issues here aswell. The idea for my needs is i need to add highlight when i mouse over.

        I got methods to detect mouse_over over an object (collider) then i get its mesh and then do stuff to the mesh.

        THe problem im facing i dont understand why this not working.

        func highlight_object(collider, is_mouse_entered:bool):
        	if collider is Item:
        		var mesh = collider.item_mesh
        		var material_count = mesh.get_surface_override_material_count()
        		for i in range(material_count):
        			var mat = mesh.get_active_material(i)
        			if is_mouse_entered:
        				var new_mat = mat.duplicate()
        				new_mat.next_pass = HIGH_LIGHT
        				mesh.set_surface_override_material(i,new_mat)
        			else:
        				mat.next_pass = null

        I got two types of items

        Hat


        Potion


        In the world i have these two scenes and duplicated them in the world tree.

        As you can see in the video the potion item works fine, i can highlight each of the items separately but the hats are wierd. One highlights the other.

        EDIT:

        I just realized that i CTRL + D in the world tree to duplicate the Hat scene, and thats why.

        Even if i set to local:

        func highlight_object(collider, is_mouse_entered:bool):
        	if collider is Item:
        		var mesh = collider.item_mesh
        		var material_count = mesh.get_surface_override_material_count()
        		for i in range(material_count):
        			var mat = mesh.get_active_material(i)
        			if is_mouse_entered:
        				var new_mat:Material = mat.duplicate()
        				new_mat.next_pass = HIGH_LIGHT
        				new_mat.resource_local_to_scene = true
        				mesh.set_surface_override_material(i,new_mat)
        				
        			else:
        				mat.next_pass = null

        Same result.

        Also tried to check the

        Not helping 🙁

          kuligs2 Set the material for the mesh instance node, not for the mesh resource. The latter will change the material for all instances that use the same resource, which is precisely what you want to avoid. So that's why there's the material_override property in the MeshInstance3D node.

            xyz

            But that is exactly what im doing here:

            kuligs2

               func highlight_object(collider, is_mouse_entered:bool):
            
            	if collider is Item:
            		var mesh = collider.item_mesh # < --------- This is MeshInstance3D node
            		var material_count = mesh.get_surface_override_material_count()
            		for i in range(material_count):
            			var mat = mesh.get_active_material(i)
            			if is_mouse_entered:
            				var new_mat:Material = mat.duplicate()
            				new_mat.next_pass = HIGH_LIGHT
            				new_mat.resource_local_to_scene = true
            				mesh.set_surface_override_material(i,new_mat)
            				
            			else:
            				mat.next_pass = null

            Im not going into the mesh resource, only meshinstance to get material count and loop through all materials and set the next pass.

            I tried to set the first material before i made the loop, and it didnt work for some reason, thats why i made the loop, and the material duplicate thing.

            Will have to debug it later.. it makes no sense.

            • xyz replied to this.

              kuligs2 What happens if you assign material directly to material_override property instead of calling set_surface_override_mateial()?

                xyz Some meshes have multiple materials hence the loop but i set it like this real quick

                func highlight_object(collider, is_mouse_entered:bool):
                	if collider is Item:
                		var mesh = collider.item_mesh
                		var material_count = mesh.get_surface_override_material_count()
                		for i in range(material_count):
                			var mat = mesh.get_active_material(i)
                			if is_mouse_entered:
                				var new_mat:Material = mat.duplicate()
                				new_mat.next_pass = HIGH_LIGHT
                				new_mat.resource_local_to_scene = true
                				mesh.material_override=new_mat #< --------------------------------------------
                				#mesh.set_surface_override_material(i,new_mat)
                				
                			else:
                				mat.next_pass = null
                			
                		
                	pass	

                Result the same

                • xyz replied to this.

                  kuligs2 Print the item_mesh when you get it from the collider to see that it is indeed a different node for each instance.

                    xyz
                    Did more tests, it seems something is broken.

                    As per some tutorial i generated "outline" mesh for the mesh, set the highlight material and set visibility to false.

                    And i get the same behavior with setting the mesh visibility that i get setting materials.

                    if i hover on one the other one lights up but not the one i hover on.

                    func highlight_object(collider, is_mouse_entered:bool):
                    	if collider is Item:
                    		var mesh = collider.item_mesh
                                    print("mesh : - ",mesh)
                    		var outline_mesh = mesh.get_child(0)
                    	
                    		if is_mouse_entered:
                    			outline_mesh.visible = true	
                    			
                    		else:
                    			outline_mesh.visible = false	

                    Printouts:

                    entered player mouse
                    mesh : - flask:<MeshInstance3D#47513077244>
                    exited player mouse
                    mesh : - flask:<MeshInstance3D#47513077244>
                    exited player mouse
                    mesh : - flask:<MeshInstance3D#47513077244>
                    entered player mouse
                    mesh : - flask:<MeshInstance3D#47513077244>

                    The thing fired twice, not sure why but i hovered on 2 different potions, seems like they are the same instance..

                    Yes i have duplicated them with CTRL + D and moved in the world tree.

                    But i dont see how can i make it unique

                    • xyz replied to this.

                      kuligs2 The problem is likely in what (and when) is assigned to your item_mesh property since it apparently has the same value for all instances. If you're assigning in editor via exported reference you should instead assign upon instantiation in _ready(). Hard to debug from screenshots though, I'm guessing here. Make a minimal reproduction project and post it so we can take a look.

                        xyz so there is no way to prototype with instnacing nodes manually using editor. Everything has to be preloaded in code then instnaced on _ready()? 🙁....

                        • xyz replied to this.

                          kuligs2 You can instance manually, just reassign the references in code at startup or try not duplicating instances via ctrl D, but instead drag each new instance to the scene from the file system window. This is a known pitfall and can be worked around in various ways depending on your project's setup and preferred workflow. Tbh I thought someone already complained about it at Godot's github. This was also discussed at length here before, so search around.

                            xyz if you know what to search for then you can search for it. I dont, i just stumbled upon this issue so i asked why things not working the way they should. Many things that you do in the engine naturally have pitfalls it seems. Anyways, thanks for the info.

                            The more you know..

                            xyz but as you say, dragging from file browser on the scene tree works as it should. Materials/meshes are setting when i hover on with mouse and printouts give me different instance ID's. Wish ctrl + D did the same, instead of dragging with mouse. Maybe they could implement CTRL + Shift +D makes duplicate of the same instance and CTRL + D makes a new instance

                              kuligs2 don't change material, use a custom shader with instance uniform.

                              if you are using a standard material, you can click on it and do convert to shader.

                              In your shader, set the things that need to change, in this case the amount of vertex displacement and maybe color and alpha, to an instance uniform:

                              instance uniform vec3 albedo : source_color;
                              instance uniform float grow = 0.0

                              you can make the effect disappear by either setting the displacement very low, or using scissor transparency and setting the scissor or alpha to 0.

                              this will add a new tab in geometry where you can change the instance uniforms. these are unique to each object, so if you change one, the others will not be affected. It also has the best performance.

                              finally, in your script you can change the uniform instances of the meshInstance3D directly, and it will affect all materials with this uniform instance name in your mesh:
                              $metarig/Skeleton3D/Hair.set_instance_shader_parameter("albedo", Color.BLACK)

                                Jesusemora this does not work.

                                Code that sets stuff on mouse over:

                                	if collider is Item:
                                		var mesh :MeshInstance3D = collider.item_mesh
                                		
                                		var material_count = mesh.get_surface_override_material_count()
                                		if is_mouse_entered:
                                			print(mesh)
                                			mesh.set_instance_shader_parameter("uniform",1.0)
                                			mesh.set_instance_shader_parameter("grow",0.05)
                                			mesh.set_instance_shader_parameter("albedo",Color.CHARTREUSE)
                                			
                                		else:
                                			mesh.set_instance_shader_parameter("uniform",0.0)
                                			mesh.set_instance_shader_parameter("grow",0.0)
                                			mesh.set_instance_shader_parameter("albedo",Color.BLACK)

                                shader code:

                                // NOTE: Shader automatically converted from Godot Engine 4.2.1.stable's StandardMaterial3D.
                                
                                shader_type spatial;
                                render_mode blend_mix,depth_draw_opaque,cull_back,diffuse_burley,specular_schlick_ggx;
                                uniform vec4 albedo : source_color;
                                uniform sampler2D texture_albedo : source_color,filter_linear_mipmap,repeat_enable;
                                uniform float point_size : hint_range(0,128);
                                uniform float roughness : hint_range(0,1);
                                uniform sampler2D texture_metallic : hint_default_white,filter_linear_mipmap,repeat_enable;
                                uniform vec4 metallic_texture_channel;
                                uniform sampler2D texture_roughness : hint_roughness_r,filter_linear_mipmap,repeat_enable;
                                uniform float specular;
                                uniform float metallic;
                                uniform vec3 uv1_scale;
                                uniform vec3 uv1_offset;
                                uniform vec3 uv2_scale;
                                uniform vec3 uv2_offset;
                                
                                
                                instance uniform float grow = 0.0;
                                
                                void vertex() {
                                	UV=UV*uv1_scale.xy+uv1_offset.xy;
                                }
                                
                                
                                
                                
                                
                                
                                void fragment() {
                                	vec2 base_uv = UV;
                                	vec4 albedo_tex = texture(texture_albedo,base_uv);
                                	ALBEDO = albedo.rgb * albedo_tex.rgb;
                                	float metallic_tex = dot(texture(texture_metallic,base_uv),metallic_texture_channel);
                                	METALLIC = metallic_tex * metallic;
                                	vec4 roughness_texture_channel = vec4(1.0,0.0,0.0,0.0);
                                	float roughness_tex = dot(texture(texture_roughness,base_uv),roughness_texture_channel);
                                	ROUGHNESS = roughness_tex * roughness;
                                	SPECULAR = specular;
                                }