16
$\begingroup$

I'm trying to create a night-time city in Blender 3.2. For streetlights I've tried two approaches with geometry nodes:

  • Instance lots of balls with an emissive texture.
  • Instance actual point lights.

Neither does much in Eevee. Emissive materials don't light surfaces. With more than 128 point lights they get ignored. Cycles is slow in both cases.

I wonder if there is a clever solution? Can I somehow bake this lighting so the roads and buildings get a fast lightmap texture? I want to animate some stuff, but the lights and buildings will be static.

Cycles render of city at night

$\endgroup$
0

1 Answer 1

16
$\begingroup$

Here is a dark city scene setup with emissive materials for the windows and emissive spheres used as street lamps (EEVEE)

Dark

As you noticed, the emissive lights do not cast light on the surrounding objects - to do this in EEVEE, you will need an Irradiance Volume. Scale the Volume to your size requirements and bake the lighting in the render properties tab. You can adjust the cube-map size if you need better resolution (right side)::

Irradiance

You can also select the Irradiance properties and change the resolution - don't go too high or performance will suffer:

Rad

Here is the scene after the bake - the lighting will stay the same until you delete the lighting cache or bake again:

Baked

$\endgroup$
1
  • $\begingroup$ Thanks, much appreciated! I haven't been able to get it working so far, but I'm still pushing the buttons and hoping for the best. (Somehow a different part of the city ends up lit than the one where I put the irradiance volume, and it's not looking great. I'll experiment with a smaller piece to get the hang of it.) $\endgroup$ May 29 at 20:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.