Some quality of life / artist friendly tweaks for vray lights directional controls

[joconnell]

Hi folks!

I was working on a shot recently where I'd to match set lighting as accurately as possible which brought me back to a few annoyances with the vray light - the directional parameter. It's got a few properties which make it a bit hard to work with so I'd love to have them looked at.

Firstly is that normally in vfx we're working to light reference where we'll match contrast ratio first and then look at sharpness or quality of light to match falloff and shadows. If we use the directional parameter of the vray light, as you increase it's value, you're also increasing the level of light hitting a surface. You're ruining your own work which is a tad annoying - if you got a note to keep everything as is but just change the shadow softness a bit you'll end up fighting the software which is time wasted. I can understand that there's a physical premise for this but it's countering what went want to achieve.




Next we get to the shape of the light throw - we'll normally have a specific cone / angle that we want to hit and then control how it feathers off between the hotspot area and darkness. With the vray light we don't get any options beyond the overall directional parameter so we're a little short here. As you can see above it's always quite a soft falloff which we don't have control over so we can try and use some flags:



So here we get a bit of control over the shape of the shadow - it's still not perfect as we don't have control over the falloff from hotspot to shadow. One upside is that our brightness value doesn't change as much though. Next we could try doing what a fresnel light would do and we could move our bulb:



Here we're getting maybe slightly better control over the shadow falloff but still not amazing. Lets try playing with the length of our flags instead:



Okay now we're getting something like what we want - we keep the hotspot in the area we like and get to control how quickly our shadows are falling off, it's just a little bit inconvenient!

Would it be possible to follow the standard max option of having an inner / outer shadow control so we could set this range by hand?

[joconnell]

Another one is on images being used as textures / gobos. Here's a light with a texture being animated from directional 0 - 1. It only really becomes useful at a value of 1 where you pretty much have a totally straight cone of light which isn't much use in day to day work. Do you think it'd be possible to have an option to apply the texture post-directional? We often try to break up our lights slightly to make them less perfect with either textures or IES and it'd be great to have the option with the vray light!



Lastly do you think it'd be possible to have vray lights support something like object properties, object ID with the multisubtex or perhaps the vray user colour map as a quick way to have a load of lights driven by data? We often have scenes with thousands of lights and it'd be great to have an option to add in mass variation from a central place.

Thanks folks!