Changing material on renderer (Entities Graphics)

[clever frigate]

So I have an Entity with various components generated from a GameObject. The gameObject this generates from has a MeshRenderer and a Mesh Filter (image 1). Traditionally, what I would do is now add my materials (its 2 I want in this case) to the Materials list of the Mesh Renderer, and then remove it again when I want my effect to disappear. How can I achieve the same effect with the entity now? My current approach looks like this:

RenderMeshArray renderMeshArray = entityManager.GetSharedComponentManaged<RenderMeshArray>(currentEntity);

List<UnityObjectRef<Material>> mats = new List<UnityObjectRef<Material>>(renderMeshArray.MaterialReferences); // First get the list of the already existing materials as my intended effect adds upon it, and doesnt replace it.
foreach(Material material in GameManager.Instance.outlineMaterials) // Add each required material from some reference somewehere
{
    mats.Add(material);
}

renderMeshArray.MaterialReferences = mats.ToArray();
ecb.SetSharedComponentManaged(currentEntity, renderMeshArray); // Set it back on the entity

This doesnt really work as after setting it it just set null (making it invisible due to even the original material and even the mesh being all overwritten with null). I think Im probably approaching this completely wrong and would like to know how it is done properly

[formal geode]

You need to use MaterialMeshInfo to swap your current material/mesh. So you bake the entity with 2 materials and change them using indices of the RenderMeshArray (can be done in a baker or at runtime) https://docs.unity3d.com/Packages/com.unity.entities.graphics@1.4/api/Unity.Rendering.MaterialMeshInfo.html

[clever frigate]

Im not sure I understand so you say I add the materials to when its still a GameObject (all of the ones I may ever need on it) and then activate/deactivate them?

[formal geode]

Or if you can't bake the materials in a subscene (accessible only in the game) then you need to use EntitiesGraphicsSystem and register your materials manualy: https://discussions.unity.com/t/best-way-to-change-material-of-an-entity-in-isystem-run-time/917798/3

[formal geode]

Yes, if it is possible then this is the easiest way. In my case materials are generated at runtime so I have to use the second method I sent

[clever frigate]

For my needs all my materials are accessible in the editor so that should be fine but I think I still dont get how its actually done

[formal geode]

Also I see you are using GameManager.Instance.outlineMaterials which would not work as you can't set materials on your meshrenderer during baking (the baker will not reflect the changes). So you probably have to use this

[clever frigate]

I was using that because from how I read the docs it looked like it expects me to use a Material just like this, which is supported by the fact that it lets me compile like this

[formal geode]

The problem is the order of baking. During baking you don't know the order of execution of bakers and thus if you change some other baker parameter it can happen before or after the other baker will run

And RenderMeshArray will not be valid because it is created using Unity's own baking system

[clever frigate]

Well, applying the material directly to the mesh just showed me that my shader doesnt even work in DOTS

[formal geode]

Probably just some HybridInstanced flags, if the shader is not hand written

[clever frigate]

Im using one from the asset store I didnt even know DOTS needed special shaders I thought it was URP compatible till now

Yeah this is my breaking point man I have no idea about shaders and just tried implementing this with a technology I never used before for hours :(

[formal geode]

Unfortunately, I am unable to help you with a shader as I myself am not a shader guru. Regular ShaderGraph shaders are compatible by default while writing your own shaders is really hard for Entity Graphics

[tardy dragon]

Yes this is the issue Im facing, you have to create custom shaders for all of your entities stuff because I've yet to come across ANY packages that offer shaders compatible with the Hybrid Renderer (which is what Entities uses).

[strange cliff]

I think the only requirement is that the shader has gpu instancing support? But I could be wrong

I do recommend just playing around with shadergraph shaders though

[rugged comet]

any property your shader relies on needs to be setup with the dots instancing support. I just assume that anything in the cbuffer also needs the dots instance setup

https://docs.unity3d.com/6000.0/Documentation/Manual/dots-instancing-shaders-declare.html