Mesh Lights with Texture Projection - FILES

I've added some basic texture projection into the fake mesh light shader. It can now project a cubemap texture or 2d texture spherically around it. The 2d mapping will need tweaking if you need it to visually match the emitter sphere, depending on how you've uv mapped that.

I've also included a version of the shader that acts as a directional projector. Unlike the standard Unity projectors, this one takes normals into account instead of projecting on to both sides of the mesh, so it can behave a bit more realistically I think, but unlike the Unity projection, it cannot limit the effect to certain layers without using multiple cameras. The next step is to sample the Shadow map in the shader, and then this could perhaps be used for a decent enough stained glass effect.

The next thing I want to do with this approach is to integrate SDFs (Signed Distance Fields) to be able to use them as flexible area lights. I'm still working this out, so that's not included in these files yet. The gif above is an initial test.

I'm pretty confident I can figure this out, but I still need to get my head around some of the details (read: the maths). I think it could be pretty useful as a cheap way to create area illumination for all sorts of primitive shapes, and also just as a convenient way to tint or colour correct an area of your world without relying on post processing volumes.

Something I'm less certain about, but hopeful: Another area I think this technique could be useful is a way to render out an environment interaction texture in screenspace, for stuff like grass/foliage interaction, water and mud/snow. The previous method I used required a top-down camera, and only really works well on flattish ground, since the environment interaction texture is projected from above, whereas I think this could work quite well to create a what's needed for a proper 3d volume. I'm not sure about this yet, I expect there's some gotcha I haven't thought about yet that would break what I have in mind, but that'll be something fun to explore later.

As always, thanks for the support, and if you have an ideas, suggestions, or corrections, please let me know in the comments or on discord or twitter.

-Ed

UPDATE - BUG FIX.

Please check out the bugfix notes here https://www.patreon.com/posts/41886173 and download the FakeLight_textureProjection_03_FIX_Unity2019.3.0f3.unitypackage from there instead of these files. That unity package contains the fix for all the variations of the fake mesh lights, including these texture projection ones.