To set up emissive maps and light masks more efficiently in Unity using Spine, you can leverage the Spine URP shaders. Here are some steps and tips to help you achieve the desired effect:

1. Use Spine URP Shaders: Ensure you have the Spine URP Shaders UPM extension package installed. This package includes shaders specifically designed for Spine animations in Unity's Universal Render Pipeline (URP).

2. Shader Selection: Use the Universal Render Pipeline/2D/Spine/Sprite shader for your materials. This shader supports emissive maps and can interact with URP 2D lights.

3. Emission Map Setup: In the material settings, you can assign an emission map. This map will define which parts of your texture emit light. Ensure your emission map is correctly set up in Spine and exported along with your main texture.

4. Rim Light Mask: For the rim light effect, you can use the emission map channel provided by the Universal Render Pipeline/Spine/Sprite shader. Adjust the emission color and intensity to achieve the desired rim light effect. If you need the rim light to react to the environment, you might need to script the emission intensity based on the light source's position relative to the character.

5. Normal and Light Maps: If you want to use normal maps for more detailed lighting effects, ensure your normal maps are correctly set up and assigned in the material settings. The Universal Render Pipeline/Spine/Sprite shader supports normal maps, which can enhance the lighting interaction on your character.

6. Example Scene: Check out the 2D/URP 2D Shaders.unity example scene provided with the Spine URP Shaders package. This scene demonstrates how to set up materials and lights for Spine animations in URP.

Here is a brief example of how to set up the material in Unity:

Material material = new Material(Shader.Find("Universal Render Pipeline/2D/Spine/Sprite"));
material.SetTexture("_MainTex", mainTexture);
material.SetTexture("_EmissionMap", emissionMap);
material.SetColor("_EmissionColor", Color.white * emissionIntensity);

For more detailed control over the rim light effect, you might need to write a custom shader or script to adjust the emission based on the light source's position.

By following these steps, you should be able to set up your emissive maps and light masks more efficiently and achieve the desired lighting effects in Unity.

Cheshirecrow Sorry the bot's answer is not helpful. However, the example scene the bot mentioned is existent. The example scene is not added to the project unless you press the Import button in the Samples section of the package manager, so I guess that's why you missed it:

After importing the examples, set the Example 2D URP Asset to Scriptable Render Pipeline Settings in Project Settings - Graphics.

Then you can check the example scene 2D/URP 2D Shaders.

I'm not very familiar with lighting, so I'm not sure if this will solve your problem, but it's worth a look if you haven't already checked it out.

Cheshirecrow Unfortunately I do not have detailed insight on that, so please wait for a response from our Unity expert Harald.

Cheshirecrow Oh, unfortunately, the setup in the scene did what I used to do for static emission maps. Do you happen to know any examples of Spine-animated emission maps that also have the correct light mask setup inside runtime?

What do you mean by static emission maps? You might want to check out this forum posting which describes the URP 2D example scene rim light setup:
https://esotericsoftware.com/forum/d/15745-2d-light-urp-light-mask-duffuse-ramp-and-specular/5

Basically it's a combination of declaring the light type for each mask channel in the Renderer2DData asset, adding a light to the scene which emits light with the respective Blend Style and then at the skeleton Material have the respective mask channel (e.g. the red channel) have a non-black value where it should receive this specific light type.

Thanks for the additional info.

Cheshirecrow The goal is to figure out an effective way to get animated emissive lights in runtime with the correct rim light which uses the red channel.

I'm afraid I don't quite understand the desired combination of rim light and emissive light here. Normally the rim light is created by outside sources, a 2D Light placed in the scene where the back of the character should be lit when moving past it. For the rim light, the skeleton's material just controls reflection intensity of such lights, via the Light Mask, limiting reflections to the rim. Emissive light on the contrary is used for light sources emitting light from the skeleton, like e.g. green fluorescent areas or glowing eyes. If you want to control the emissive map's intensity at runtime, you normally set the emissive map to cover only the glowing areas, and then change the color parameter next to it accordingly, which is multiplied with the mask. You can then use e.g. a MaterialPropertyBlock to avoid creating material duplicates.

Cheshirecrow I didn't find any option to set the light mask to only use a red light channel like what I used to do.

Here's an example of what the light mask is supposed to look like:

If like in the short video section you posted earlier, this looks more like you want to place a 2D Light in the scene at the respective location (or let the position move with a bone via a BoneFollower) and then let it light your skeleton. How did you originally create this lighting effect? Why can't you reproduce it with the Light Mask now, what prevents it from working?

Cheshirecrow The emission map should be animated on or off depending on its active states and I achieved that by animating an 'additive' layer inside Spine and then exporting it into Unity.

Thanks for sharing the details. Unfortunately I don't quite understand, why don't you use the additive slot blend mode any more if it worked before? Or did you run into problems making the additive blend mode work with URP?

Cheshirecrow But now I can't set up the light mask like I used to do as that wouldn't fit in with this atlas

You don't pack mask or normal textures into the atlas, you need to have an identical atlas texture for the mask where only these regions are not black.

Cheshirecrow I would create a 2D Light at the respective position and vary it's intensity over time. If you need to mask the effect to some parts of the skeleton, then have the 2D light's Blend Style set to be e.g. rim. Then let the mask atlas texture at the skeleton only be non-black (in e.g. the red channel) where you want the light to affect the skeleton.

Note that the mask texture is a copy of the normal atlas texture with identical layout, not adding mask attachments to your normal atlas texture. You can ensure the identical layout by creating the mask atlas texture from the output normal atlas texture, or pack attachments by folder structure and ensure that all attachments to be packed are of the same size and have Strip whitespace X/Y disabled to ensure all are packed with identical layout.

If I misunderstood your question, please let me know.

Cheshirecrow Do you mean adding another 'Light blending style' and using additional lights to control the emission map aside from rim lights?

Sorry if the description didn't help. I was mostly describing how to create the lighting effect for the second video you posted, the one with the walking robot below the text "Here's an example of what the light mask is supposed to look like". Your example of the rolling ball is actually a bit different.

Regarding your first video with the multiple red lights at the ball, plus the white rim mask:
The red lights and the rim are completely separate things. For the white rim, if the ball would not be rolling: the rim atlas texture should be assigned at the Light Mask with only these atlas parts non-black where the rim light should be displayed. Then place 2D Lights in your environment with Blend Style set to Rim. And don't set the rim light attachment slot to Blend Mode Additive, you want to use the 2D Light to light the masked parts. That all applies if the ball would not be rolling.

Since the ball is rolling, you have the problem that the rim moves with it. To fix that would require the attachment to be separate and aligned horizontally via e.g. a TransformConstraint or overriding bone location programmatically, or using a similar solutions to keep the bone horizontal. Since you can't separately rotate the rim mask texture from the normal color texture at a single attachment, you need to have two separate bones with separate attachments. This fixes the orientation part of the problem. The light-attachment at the top could have Blend Mode Additive. Then you would enable the material parameter Light Affects Additive, so that the 2D Lights are multiplied with the additive color. With this combination, you should not need a mask for this rim light any more, as the light is multiplied already with the additive texture, resulting in the mask effect.

Regarding the multiple red lights: I'm not quite sure what the exact problem with those was, but you can simply enable the Emission property and assign the emission atlas texture there (again, identical in layout to the normal atlas texture, only white where the red lights are), then modify the color property next to it (programmatically e.g. via MaterialPropertyBlock to avoid material copies).