Directional value darkens light appearance

[PixelJockey]

I don't know if this a bug or a feature. And I don't recall this happening in earlier releases. But when you increase the directional value of a rectangle or disk light the appearance of the light becomes darker. If the light is facing the camera it will still be bright. Although using a directional value of 1 will still appear black when facing the camera.

In the attached image I have a series of rectangle lights with the directional value increasing from 0 to 1 in .1 increments. All of the lights multipliers are set to the default 30. The lights that face down at the floor slowly turn black as the value increases. There are instances of the lights above that have the light target aligned to the cameras pivot point.

If this is a feature it seems kind of strange and not really useful. I'm really scratching my head to think of a time when you would want this behavior. It took me a while this morning to figure out why my lights were appearing black instead of white.

[Rens]

Viewed in the direction of the light it would appear very bright. This is mimicking real life behavior of directional lights where they are much less bright when viewing from the side, a laser light for example. The only difference is that their real-life counterparts usually have some light scattering in all directions still from for example the light housing or imperfections etc, so it would be more of a blend between very diffuse and directional.

Not sure if there's an easy way to blend diffuse and directional lights in the same position.

[cheerioboy]

http://forums.chaosgroup.com/showthr...034#post622034

It has been an issue (or feature?) for a while. It has gotten me into the habit of putting geometry lights in my scenes and keeping the vray lights invisible.

[vlado]

At some point we will modify the directional light distribution to have a longer "tail" (similar to GGX for reflections), so that it's not completely black from the sides.

Best regards,
Vlado

[PixelJockey]

Thanks for the feedback. I did a forum search but didn't see cheerioboy's post.

I had a model set up with vray lights for the downlights. This was in the early stage of the model and light placement/fixtures hadn't been selected yet. I just needed something quick to set up and light the scene. But the client wanted to know why the lights were turning black in the distance. I'll make sure to use geometry in the future.

[NicoC]

It's a recurrent problem with renderers apparently ... but there are solutions (check around the middle of the page): https://corona-renderer.com/blog/1-6...view-feb-2017/

[Art48]

I would still absolutely LOVE to have a VRayLight mimicking the behaviour of the standard max spotlight. Having settings for manual falloff curves, manual decay etc. We use Spotlights all the time for high end product visualizations and I know it doesn't have a reflection component for example. I mean it works...but a native VRayLight solution would be much preferred.

[NicoC]

I would still absolutely LOVE to have a VRayLight mimicking the behaviour of the standard max spotlight. Having settings for manual falloff curves, manual decay etc.

Oh yes ... a way to override physical behavior when needed would definitely help !