Vray Light / LightMtl Opacity - Creating highlights only, real Softbox-like?

[JAPAN_DIGITAL_IMAGE]

Hi everybody

I am a big fan of VraySoftbox - really helps with beautiful product lighting.
I am having trouble creating a studio-like lighting though because the black part of my softbox gradients will be reflected and visible as black if there is another light source behind the light.
Because lights are on top of each (or rather behind each other, especially when using a dome light as a base light) the gradient I want to be reflected on the surface will also have the black part.
Which is not how it would work in a dome lighting environment for e.g. a car photoshoot. The lights and their highlights would mix with each other on the studios wall or the paper-dome and thus black parts will not show.

Now I gave up on the idea on using Vraylights to achieve this, because VrayLight doesnt support opacity. No way to make a vray light transparent by a map, right?

Now I am using the Vray light material on a plane mesh, using softbox map in the the opacity slot as well...I thought naturally just the bright part of the map will be visible and the black parts will become transparent. But apparently its not like that..even when the opacity map is totally black, the light material is still visible and thus the black part of the softbox gradient too.

How can I achieve what I want to do?

Thank you. Any help is appreciated.

Manuel

[simmsimaging]

I'm not sure I agree that the black part of your lights would disappear in real life, but maybe I misunderstand you.

Anyway, I do that kind of soft floating hotspot all the time with the VRayLightMaterial - it definitely can work. Do you have the option ticked in the VrayLightMaterial "multiply color by opacity"? That should knock out the black edges etc.

b

[JAPAN_DIGITAL_IMAGE]

I am not talking about softbox-lighting. softboxes behind each other would of course also reflect for example their black borders etc.

What I want to achieve is dome lighting, like the example photo I attached.

Or like in a dome studio where you project lights onto a white wall and lower camera exposure so that this white wall would appear black until there is light projected onto it and thus reflects only highlights onto the object. This way the different lights and their gradients blend into each other.

I am currently trying the same thing that you are talking about but I have the feeling that there are still dark reflections...

[joconnell]

I see what you mean - you're not shining the light directly at the car, you're shining the light at a wall an the car is showing the reflection of the wall instead, so if you've got two lights then the hotspots generated by the light can blend together, as opposed to using the lights like cards that are directly reflected in the surface of your object.

[RE:FORM_STUDIOS]

Looks like you just need to make a similar geo with a vray2sided material applied. Shine the lights onto the outside surface. You might need copies of the ligths to seperate out the GI/lighting contribution from the relfections though.

[simmsimaging]

What you show in the pic isn't quite what was described, but the method should work. I use it for pretty much exactly that purpose (to create soft floating gradients of light) mimicing lights on a studio wall. It should work just fine.

There are other ways to accomplish what you want, but unless you are combining a tent, like your photo shows, with actual softboxes with geometry, it shouldn't be a problem for sure.

[simmsimaging]

You might want to look at HDR Light Studio too btw. For that kind of lighting it is really, really good and it's a very fast workflow.

Gotta buy it though

b

[JAPAN_DIGITAL_IMAGE]

I could shine lights onto a dome and then be able to recreate the same lighting as in a studio. But I would rather cheat and make transparent lights because it is a waste of calculation for the light bounces and then it is harder to light that way instead of just directly directing the light onto the object.
Thats what 3D and Vray should be able to, right? make it more practical and free than reality.
HDR lights are not flexible enough..

[kagemaru]

I'm not sure if this is supported just in nightly builds, but vraylights DO support trasparency (at least in reflection).
I just made a test, plugging a vraysoftbox inside an output map, with "alpha from RGB intensity", as texture for a vraylight, and i get semi-transparent edges in reflections.

Just VraySoftBox



VraySoftBox inside an output map

[JAPAN_DIGITAL_IMAGE]

WOW! Thats beautiful! It does work! Even in the normal Vray version.
I am amazed!

What a bothersome way to achieve it and not even talking about that this is really supposed to be a optional mapping solution inside the vray light.
but at least from now I will be able to cheat myself through a terrific virtual dome studio photoshoot.

thanks for sharing that secret with us Really appreciated!

[kagemaru]

Well, it's not what i would call a cheat, if you want trasparency you need an alpha
Anyway glad it helped.
Cheers.

[JAPAN_DIGITAL_IMAGE]

Well, everything and nothing is cheating when it comes to 3D, right?
I mean, from a physical point of view, transparent lights are just not existent. So instead of going the hard road of a dome studio with bounced lights, I am cheating with alpha

cheers~!

[kagemaru]

Yes, of course, i was't disputing the "cheatness" of 3d ehhehehe.
I was just saying that if you want trasparency, you need an alpha right? It works in this way in just about every software

[Guest]

I am looking to create this exact same thing as a setup as I render a lot of small objects. Looking to re-create this: http://www.tabletopstudio.co.uk/Page...20Kit%2030.htm. Rather than the two side lights coming through the fabric I am using EXR images in a V-Ray light material that has the hot spots, creases and shadows of the fabric.

[JAPAN_DIGITAL_IMAGE]

Why dont you use normal Vray lights and the method we were just talking about?
it is easier to handle..