Parallel emission feature?

[Bulwerk]

I would be interested in the ability to "focus" a lights projection along a continuum. Currently light is emitted fundamentally in all directions from the normal (as real lights do) if I understand correctly.

But what if we could weight the ray direction based on surface normal 0=multidirectional 1=perpendicular to surface.

Mainly I see this being used to creating perfectly parallel spot lights but could also create interesting effects for mesh based lighting.

[frankmci]

Even with how far as rendering has come in the last decade or so, which is truly mind boggling, I do miss a lot of the fakes that used to be our bread and butter, like ubiquitous "directional lights," and "environmental reflection" texture maps.

[Hesekiel2517]

As far as I know this can already be done with the distribution channel. There is also a Spotlight Texture to create a texture for this.

[frankmci]

I recently saw this video from Silverwing which uses Octane Sky to add multiple distant/effectively parallel lights using gradient nodes. It's a little cumbersome to set up, compared to just using distant spotlights, but it's also quite elegant in its own way. I was thinking it would be fairly easy to link the Transform controls to appropriate geometry/curves for more direct, intuitive aiming in world space. You could build a Sky rig with half a dozen pre-built directional lights on it and keep it in your toolbox.
https://youtu.be/535cMPQjv3g

[frankmci]

Haven't seen the video yet but it reminds me of this technique from this page

It's a similar idea, but using layered gradient nodes in a procedurally generated HDR environment texture to generate multiple light sources. One advantage over just using the Sun light in a black sky is that these lights work perfectly well when rotated below the horizon.