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benedict_ilagan
12-29-2013, 08:51 PM
Season's Greetings!

Hi guys,

Is there any link or feature in lightwave regarding object light??

As the title says object light, were we can assign the object surface material as a light source of a scene like garden lamp see image attachment:

Hope for your quick response. thanks

Snosrap
12-29-2013, 10:20 PM
Luminosity in the Basic tab of the Surface Editor. You can use values over 100% if you want/need. If you use Radiosity the surface will actually give off light - otherwise it just glows brightly. Here is a sphere on a plane.

benedict_ilagan
12-30-2013, 02:32 AM
Luminosity in the Basic tab of the Surface Editor. You can use values over 100% if you want/need. If you use Radiosity the surface will actually give off light - otherwise it just glows brightly. Here is a sphere on a plane.


Thanks so much Snosrap,
I've tried that before with luminosity above 100% but the lighting is fake, i mean the object doesn't illuminates as a point light or behaves like a soft light. I even placed a point light inside of an object to simulate a light casting on surfaces but the idea is not real.

Under Octane render has one feature & it's called blackbody where it shines like a real light behavior when assign to an object. I've tried working with octane render on 3ds max during a pipeline project & OR is also in LW that would be a sure solution.

But I'm thinking of a native way for LW to work similar on lamp sample.
Hoping for more suggestions and ideas, guys.

danielkaiser
12-30-2013, 05:27 AM
Never used it but there's DP Custom that can set an object as a light source it's part of DP light.

zardoz
12-30-2013, 07:35 AM
hmmm like snosrap said, are you using Global Illumination (like Monte Carlo)? if you give a surface a luminosity value (you can use anything from 0% to 1000% or more, whatever works with the scene scale) and if you have Global illumination on it will work fine, even using an inverse square as a falloff..

spherical
12-30-2013, 11:45 PM
I've tried that before with luminosity above 100% but the lighting is fake, i mean the object doesn't illuminates as a point light or behaves like a soft light. I even placed a point light inside of an object to simulate a light casting on surfaces but the idea is not real.

If you're using an object that has a surface, it will "behave like a soft light". It won't look like a point light illumination because it has surface area that is far larger than a point. Not to make a pun but that's the point of making a surface luminous.

Tobian
12-31-2013, 10:13 AM
Yeah Dikie, sounds like you're doing something wrong if you can't get radiosity to work right... the Radiosity engine works perfectly fine, and accurately, it's just slow and can be blotchy with some scenarios. Radiosity using luminous surfaces is far more realistic than using lights. especially if you're using a PBRT workflow. Are you working in sRGB workflow?

jeric_synergy
12-31-2013, 12:46 PM
(away from machine) Maybe an example with a long, linear, squiggly mesh would illustrate this better.

The feature has always worked for me, although the render times can be brutal.

benedict_ilagan
12-31-2013, 08:15 PM
Thanks guys for those great ideas,

zardoz theory is true but the luminosity seems light behaves unnaturally coz of lack of light temperature (soft yellow) wc emits & causes an atmospheric glow seen on outer of the rim like on the sample pic. Yeah, that can be done on adding on post work or even with a very little value of glow feature that LW surface has. :)

UnCommonGrafx
01-01-2014, 06:34 AM
That, dponts filter kit, corona or some such tool that will give you some haze/atmosphere will help.
Temperature for such a surface is decided by you; lacking it suggests you left the surface color white or cranked the luminosity too high as you should get color bleed and all that good stuff from the radiosity engine.
Even with the Octane emissions, I have found I have to reduce the emissions to silly low levels (.05 one time). I am learning to equate that to a 50 to 75% range for luminosity when trying to light a scene the same as Octane.

It's the haze and bloom-age you are really looking for, I bet: Octane's renderer benefits from having an atmosphere ON by default. Makes the mood travel better as you test your renders.

jwiede
01-01-2014, 06:38 AM
Thanks guys for those great ideas,

zardoz theory is true but the luminosity seems light behaves unnaturally coz of lack of light temperature (soft yellow) wc emits & causes an atmospheric glow seen on outer of the rim like on the sample pic. Yeah, that can be done on adding on post work or even with a very little value of glow feature that LW surface has. :)

Those effects are due to the tiny level of atmospheric haze always present in real life. You should be able to replicate such effects in LW, you'd need to activate volumetric fog at a minimal amount to achieve it (and volumetric GI, etc.). Beware, though, render times will become painful -- using post fx (either in LW as glow, or in comp) for such effects is usually much more efficient, but LW can do it if you must have it rendered.

djwaterman
01-01-2014, 07:44 AM
That glow in the picture is really a photographic effect, so it's happening in the camera, best done in post. I think LW has some built in post type filters that I've never (and would never) use, why beat yourself up trying to get that in your render, it's not cheating to achieve that in post.

Tobian
01-01-2014, 07:51 AM
Those effects are due to atmospherics, particulates, DOF and Fraunhofer driffraction, in the lens aperture, over and above lens reflections... With the exception of DOF, Lightwave handles none of those things. You can fake some of them with 'glow' or using better stuff, like DP's filter, but it's not as good. Very few rendering engines offer a complete model though, and it's not always right. You're probably better at handling them with post, but it's quite difficult to do a full model/ period, and even the full PBRT renderers like Maxwell or Octane don't do everything or do it right.

With regards to colour temperature, and emissivity, as I said make sure you are using the srgb colour model in your lightwave settings, this will mitigate most of the colour bleed issues and give your light bounce the correct light penetration into the scene. If you take a look at my website, all of my renders are done ONLY in Lightwave, and then I apply post processing in AfterFX to get the bloom and glow effects. All of the interiors are entirely lit by radiosity ONLY (except for sunlight coming through the window in some cases, which is a dome light, with a small radius). Note as Zardoz said, you need HIGH values in your luminosity. Typically I have between 300-1500% brightness for luminous surfaces, and most of them have subtle colour. There's a colour temperature mode in the LW colour picker, if you want to emulate that, but don't confuse emissive power with colour temperature. In a lot of real-world lights the colour temperature and emission spectrum is emulated, so it's not a function of the black body radiance.

The other thing is exposure. Lighwave has no exposure model.. everything is at a unified exposure level, so nothing is interconnected with real values. In the real world the relative light level of sunlight as compared to interior lighting may be 10-100% different, but we tend to normalise it a bit too much in the 3D world, especially in Lightwave, because there's no exposure control.

UnCommonGrafx
01-01-2014, 08:07 AM
Tobian,
With regards your afx process, do you create a lot of buffers, too? I remember you posted some material on Radiosity, iirc, that was quite beneficial to understanding the new system.

Looks like you even speak to the ops question: http://www.andrewcomb.com/pluto_station/the-lightwave-users-group-webinar/

Great looking stuff.

Tobian
01-01-2014, 08:10 AM
No need to do extra buffers for my workflow, I just save out the whole dynamic range image, and use that as the basis for the filtering. Yes I do cover some of the advanced shading methods I use in my talk. I was a bit nervous, so I am not sure of how much use it is :D

djwaterman
01-01-2014, 06:51 PM
Loved what I saw of the presentation, wished I could have downloaded it. I wasn't able to sit through it all so will have to get back to it soon.

Tobian
01-01-2014, 07:11 PM
Yeah it was a shame, but it's the system they use. and yes, if you thought it went on for a while, at this end it seemed like an infinite amount of time :D

benedict_ilagan
01-02-2014, 12:24 AM
thanks tobian on your insights, hope we can also see color correction within LW much like a photoshop way style of handling on raw image grading. That would mean less post works too.

Tobian
01-02-2014, 05:43 AM
Yes I'd love to see a realtime compositor in LW, unify all the filters post and grading into a realtime environment, using vpr...

jeric_synergy
01-02-2014, 10:31 AM
Not me: talk about dragging devs away from the core app.

There's a million-item wish list ahead of 'integrated compositor' that IMO they should address first. Most Blender users aren't using Blender's built-in compositor, judging by the forums, so that's a sign that such a feature would be a big ol' red herring.

Lor
01-08-2014, 12:08 PM
Shader lum and Radiosity is not a viable solution for illuminated object renders due to the brutal render time and poor quality. NewTek has taken a first step toward a geometry light with the "nGon" light. It really needs to be able to set a piece of geometry as a light source. The results are much smoother and faster to render. The geometry light is a standard in other professional renderers and seriously needs to be added here. It's now a missing tool when compared to other renderers.

lor

spherical
01-08-2014, 03:36 PM
Use Dpont's Web Light.

Lewis
01-08-2014, 05:11 PM
Use Dpont's Web Light.

DP_WEb light is just Denis' verison of Photometric Light (damn good one since it has more features than native one), you probably meant to say DP_Custom light, that one can load geometry.

spherical
01-08-2014, 10:41 PM
Ah, yes, that's the one. Thanks. I used it for a luminous core to one of our blown glass table bases. Works great.