Best way to create part of a mesh that acts as a light source

Note that 4 is the default max number of simultaneous lights, but you can raise this value with material.maxSimultaneousLights.

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Here is one of my projects - Mu-so Qb 2nd Generation - 3D Demo
In order to achieve “realistic” or even “better than realistic” view there were used: Glow, Sheen, ClearCoat, imageProcessingConfiguration.
Glow is dynamic (look at logo).
No lights at all, except environment.
The source is open, one may use any part of it.
On the rear panel of the model there is blinking LED - possible solution for the light flickering in your scene.

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A Lot of Lights demo - Babylon.js Playground

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You have to be very creative with very few “real” light sources…

The scene in question I wonder if you could make the lights simple holes in the geometry and surround the whole thing with a lightbox maybe?

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Thread resurrection commence :slight_smile:

I’ve been doing some other things related to lighting. I have however determined to use one of the following solutions:

  1. Use the “lots of lights” demo as a base and try to dynamically turn of lighting when player cannot see them, and also use the includedOnlyMeshes too to battle the lighting limit. However, I’m currently using instancing to create my game map from pieces… And I have problems to get this working. Are there any limitations to this method using instances? If I change the lots of lights -demo to use instancing of spheres instead of cloning, only some spheres are lit… :thinking: See: https://playground.babylonjs.com/#WJWSNL#1

  2. Use hemispheric light and add some stencil buffer “lights” to spice up the corridors. For example something like: Wind Waker Style Firefly Lights — polycount or Procedural Pixel Art Fire - YouTube … Do you think these would be possible in Babylon?

  3. Just give up lighting and paint shadows to textures. Such example is here (also using ambient occlusion): Break Room - 3D model by lampy (@lampysprites) [708c30f] - Sketchfab

Are there some limitations with the lights and their includedOnlyMeshes property? I made a test to light the instance (sphere) with point light using includedOnlyMeshes after two seconds and nothing happens. See: https://playground.babylonjs.com/#1FUKMR#4

If the original sphere is used, everything works… :grimacing:

Edit:
Digged into some code and found this:
image
Could someone explain what this means in laymans terms? If I have an instanced mesh, the lighting of it cannot be changed? :exploding_head:

Hmmm, I see! But is it possible to not do this in the same tick? In my real project, I would like to create lights dynamically when I create the map from mesh pieces… So the scene has already been initialized, I just add stuff into it :grinning_face_with_smiling_eyes:

Anyone having an idea why the instanced sphere doesn’t update in https://playground.babylonjs.com/#1FUKMR#4 when created in setTimeout? Does this have to do with the picture I posted before, as in instanced meshes lights are coded in a way they do not update the lights afterwards? :slight_smile:

Also, does anyone know if there are any plans for “area lights”, such as in Unity. Here is a link to their docs, area lights are in the bottom of the page: Unity - Manual: Types of light

Adding @Evgeni_Popov to double check as he is the instances king :slight_smile:

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This thread has been split to Creating lights dynamically that effect instanced meshes with includedOnlyMeshes

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tenor
Hi everyone!

I’ve been theorycrafting my use case a lot during these few months but I need some help to validate the “solution” I’m thinking of doing.

So, I’m thinking of creating two versions of the texture, the “lights on” and “lights off” versions for each wall/floor mesh. Then, I would place an invisible sphere to each fake “light source” which would be the light radius. If the sphere exists, it would show the “lights on” version of the mesh texture where it touches/intersects. If not, it would be the “lights off” one. The other solution would be to not have a “lights off” version of the texture, but just turn it a lot darker.

What would be the best action to make this kind of system. I’ve been thinking of playing with stencil buffer to somehow do this, or to dive into shaders a bit more… What do you guys think of this and what do you think would be the best course of action to do this? :sunglasses:

sounds like it could work but maybe @PatrickRyan would have some tricks to fake it ?

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If you are wondering about the use case and don’t want to spend time reading everything…
I need some kind of “realtime” lighting that would come from some sources, like walls. May not use real lights since they are too expensive. Can’t bake lightmaps because the map is generated from mesh pieces dynamically.

I would like to build an electricity system in the game, where electricity source is connected to the “lamp” and if electricity turns off the light turns off. In the “solution” earlier I wondered if I could do this by creating a sphere and showing different texture or darkened texture when the sphere is not enabled or it is shrinked. No idea if this would look good though, but is is an idea at least :smiley:

I am wondering if you could generate two lightmaps one all lights on and one all lights off.

and then having a custom shader to fetch from the right texture depending on a custom attribute value ?

This is pretty cluncky but at least you could control each light independently per vertex without increasing your number of draw calls too much ?

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Generating lightmaps would be nice but I plan to make the whole map from 2m x 2m mesh pieces, where the floor and walls are also in quite many pieces. So I would need to predict all the combinations and also there is the problem that I could not have large areas lit simultaneously… Or that is what I assume at least! Take the picture below as an example. Each square is a wall/floor piece. If the lamp is attached to the wall, it might lit things up to 4+ meters and cover many floor tiles… And of course there is the problem when we add other game objects like furniture in the mix… Oh boy what have I gotten myself into :smiley:

But the lighting in this case would not need to be so realistic, since I am doing a pretty cartoonish game. So I am thinking of something like Zelda: Wind Waker style. Take the end result of this video for example: Unity: Luces volumétricas (Como en Zelda Wind Waker) - YouTube
There is the yellow light that in my case would be just the normal color of the “lights on” texture, and then all the rest could basically be pitch black or just really dark…

ohhhh that makes me think to something :slight_smile: How many lights max do you have per mesh ?

I wonder if you could limit each mesh to include only the impactfull lights so that basically most meshes would fall under the max limit cause if they are lets say point light all the meshes would not be impacted by all the lights ?

Just thinking out loud here :slight_smile:

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Yeah, the problem with this is that the meshes are instanced and the big boss said that you cannot use includedOnlyMeshes with instanced meshes, or that it only works with the main mesh? Creating lights dynamically that effect instanced meshes with includedOnlyMeshes - #2 by Deltakosh
Or so I at least understood :smiley: So I can’t just instantiate the wall piece and try to tinker with what lights it accepts…

Ohhhhh they are instanced as well so, yup I guess you d need a special trick :frowning:

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Yeap! That’s why I am currently interested in stencil buffer / shaders… But I would need someone wiser than me to tell me if it viable :smiley:

Yup and I hope @PatrickRyan that we summoned to be this person :slight_smile:

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