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Pixelight
04-27-2011, 08:55 PM
Is there a way to turn an object or model into a light, meaning making this object illuminate and cast shadows on other objects and the scene? I know you can make it glow etc. But I would like it to be the source of light in the scene. Thanks.

Sekhar
04-27-2011, 09:13 PM
Use Lexigons. In Modeler, with the object in window, run "Add Lexigon" - Modeler will let you specify the type of light, etc. and add one light for each poly. Then in Layout, run "Convert Lexigons" (you might have search for it since it may not be listed by default) and Layout will convert each Lexigon into the light you select for cloning.

IMI
04-27-2011, 09:20 PM
Sekhar, I don't think that's what he meant, luxigons only create a regular light where a polygon is.
I think he meant how to make an object itself the light source, such as you can do in Vray.

Short answer is, you can't. The closest you can get to it is to make it ambient and glowing and use GI. With GI or Final Gather, all ambient surfaces will contribute to the lighting in a scene.
But unless there's some plugin for it somewhere, you can't actually make an object a light in LW.

nickdigital
04-27-2011, 09:20 PM
You could also try the Custom light in DP Light.
http://dpont.pagesperso-orange.fr/plugins/lights/Additional_Lights.html

Pixelight
04-27-2011, 09:31 PM
So you can't? Really? I'm surprised. :(
So if you want for example to have a TV in a dark room and the TV screen be the light source you can't?
Or if you want a clock radio in a dark room and the only light is coming form the digital numbers?

JeffrySG
04-27-2011, 09:35 PM
It's actually very very simple. If you use raydiosity any luminous object will behave as a light source just like in the real world. Many people will light their scenes with no 'lights' at all. Just luminous objects.

This was a test scene I did for the quadpanels plugin that used no lights...
http://www.newtek.com/forums/attachment.php?attachmentid=85704&d=1276790002

IMI
04-27-2011, 09:37 PM
So you can't? Really? I'm surprised. :(
So if you want for example to have a TV in a dark room and the TV screen be the light source you can't?
Or if you want a clock radio in a dark room and the only light is coming form the digital numbers?


Don't be surprised, this is Lightwave we're talking about here, the most static and under-developed 3D program in the past 5 years. ;)

Well as I said, you can fake it with ambient materials and GI, to a certain extent, and there might be some magic combination of node shaders you can use to enhance it.
But in your TV example, just place an area light right in front of the screen at the same size and make the screen a little ambient as well to add to the illusion.

I don't really understand what that plugin nickdigital linked to above does, but maybe that could be an option.

Edit:
Jeffrey beat me to it, but that's pretty much how everyone does it in LW far as I know.

daforum
04-28-2011, 02:34 AM
It's actually very very simple. If you use raydiosity any luminous object will behave as a light source just like in the real world. Many people will light their scenes with no 'lights' at all. Just luminous objects.

This was a test scene I did for the quadpanels plugin that used no lights...
http://www.newtek.com/forums/attachment.php?attachmentid=85704&d=1276790002

JeffrySG that looks great!
I did sort of know that scenes could be lit with luminous objects but I didn't know that they could be lit without lights.
Thank you :)

As reference, what percentage/ brightness were the luminous objects?

IMI
04-28-2011, 02:51 AM
You read that? Good morning, time to check your "facts". And since when is using self-illuminated objects with GI a "fake"? It's just one technique of several.

How to use objects as light sources: http://dpont.pagesperso-orange.fr/plugins/lights/Lights.html#Custom - more specific version of nickDigital's link. Not that hard to understand actually.

EDIT: Ah, edited your post... so you checked the facts. See, always good to try and learn something new.

Jeez, Oliver - chill, no need to get sarcastic and condescending.

I didn't say self-illumination with GI was a fake. Seems to me I'm the first person in this thread to have mentioned it as a method, actually. ;)
It is, however, not the SAME THING as what the OP asked for. I'm fairly certain he meant in the same way VRay and some mental ray plugins can do it, where the object itself become a light with the ability to cast ray-traced shadows without using GI.
And while the DP light plugin may be *exactly* what he was looking for, it's not a native LW thing, which is also what I believe he was asking about.
And I did also imply that there may be additional plugins available for this in my very first post.

IMI
04-28-2011, 03:48 AM
Actually, something like this I believe you can do with a spotlight - just place it at the position of the TV screen and project an image or series of images/movie file. I believe I've done this before years ago without a problem. And you don't need GI to do it.
<snip>


You know, that's a damn good idea, really, and I didn't think about that. :thumbsup:
Yeah you can do lots with spotlights and projecting images and/or using gobos.

IMI
04-28-2011, 06:25 AM
Ah, sorry, looked to me like a perfectly reasonable time to be unnecessarily condescending, after a rather unnecessary remark towards lightwaves shortcomings. But no worries... :thumbsup:

Well I did put one of these after said comment --> ;)

Okay fine, so maybe I should have omitted that part, but it's not like I stepped on your cat's tail or something. My comment wasn't directed at you so I see no reason to take it personally.

lardbros
04-28-2011, 06:30 AM
Jeez, Oliver - chill, no need to get sarcastic and condescending.

I didn't say self-illumination with GI was a fake. Seems to me I'm the first person in this thread to have mentioned it as a method, actually. ;)
It is, however, not the SAME THING as what the OP asked for. I'm fairly certain he meant in the same way VRay and some mental ray plugins can do it, where the object itself become a light with the ability to cast ray-traced shadows without using GI.
And while the DP light plugin may be *exactly* what he was looking for, it's not a native LW thing, which is also what I believe he was asking about.
And I did also imply that there may be additional plugins available for this in my very first post.

Just to quickly add to the converstation...

Mental Ray doesn't have a light you can attach to objects (atleast not in 3ds max)... the only way to do the object light thing is by adding a material property the same way you would in Lightwave... certainly not a fake way at all, but a good way.

The plugin that DPont made is a light that you add a geometry to which will then cast light. You can even animate this object with morphs etc, and the light will emit accordingly... clever stuff!

I know you've already been pounded for dismissing lightwave as being able to do this, but please double check before saying it can't, gives the old Lightwave a bad name! :(



To help you a bit Pixelight... the luminosity does need to be very high to get a visible effect... around the 1000% mark will show some light, depending on the scale of your scene.

Also, when you get into adding the Radiosity, I've found that reducing the 'Multiplier' at the bottom of the Radiosity panel to 50% will make a cleaner solution around corners etc. This acts as the resolution of the Radiosity solution... so 50% means that the solution will be half the size of the camera resolution. This can smooth out a solution a bit, and make it look nicer.

SBowie
04-28-2011, 06:48 AM
'To err is human ...'

I have several books on public speaking, and communication generally. One of them makes the bold statement "Rudeness is never called for". I think that's a fine goal. (I might add that, in my experience, rudeness - in any of its variegated colours - is also never constructive.)

Not singling anyone out here, just an aside on skillful communication ... and of course, a well-known shortcoming of electronic media is its annoying penchant for seeming rude when that was not intended. It takes painstaking attention to avoid this.

IMI
04-28-2011, 07:00 AM
I know you've already been pounded for dismissing lightwave as being able to do this, but please double check before saying it can't, gives the old Lightwave a bad name! :(




I don't get the impression I've been "pounded".
Nothing I said about LW was untrue as far as the lights go.
The guy asked if you could make an object cast light in LW, and I figured he meant like the way VRay can do it, considering he said "I would like to make it the source of the light". and "...illuminate and cast shadows on other objects."

Truth is though, LW *can't* do that, without an external plugin, not in the way he meant it.

lardbros
04-28-2011, 07:08 AM
Don't worry, I'm not having a go at all... and okay, pounded was the wrong word, sorry about that.

But in Lightwave if you have a luminous object, it IS casting light, and shadows. It's exactly the same as an area light (if you use a square) or a spherical light (if you use a sphere). So, not to keep on, but the actual truth is that Lightwave CAN do this without a 3rd party plugin... the plugin just does it in a different way.

Danner
04-28-2011, 07:33 AM
But in Lightwave if you have a luminous object, it IS casting light, and shadows. It's exactly the same as an area light (if you use a square) or a spherical light (if you use a sphere).


Area lights act a bit different than luminous object, sometimes they are better sometimes they are worse. If you put a large area light on a window, the lighting will be nicer (more defined shadows) than a luminous object, but it will be noisier and it will take much longer to render.

I use (super)luminous objects to light scenes very often, they are fast and give smooth results. Use a shape close to the light sources (lamp shades windows and so forth) and hide them from the camera.

IMI
04-28-2011, 07:35 AM
Don't worry, I'm not having a go at all... and okay, pounded was the wrong word, sorry about that.

But in Lightwave if you have a luminous object, it IS casting light, and shadows. It's exactly the same as an area light (if you use a square) or a spherical light (if you use a sphere). So, not to keep on, but the actual truth is that Lightwave CAN do this without a 3rd party plugin... the plugin just does it in a different way.

Well again, I never disputed that. In fact I was the first one to suggest using a luminous object with GI.
I guess unless the OP comes back and clarifies *exactly* what he wanted, we could go on about his forever.
My assertion, however, and I think I'm right, is that he wanted an object to behave as if it were a ray-trace light. Not with GI, but like a point light or an area light is.
My answer was not wrong, considering the above. If I misunderstood him that's one thing, but I don't think I did.

Pixelight
04-28-2011, 07:49 AM
Wow, seems like the discussion has gone a bit off topic and became a little "inflamed" :D

Thanks for the suggestions. The luxigon thing seem like it could do the trick. I did some tests with simple geometry and it could work. However I can't apply it to text. Won't luxigons work on polygons within text?

By the way is the DPlight plug-in a free plug-in? I couldn't see a price on their website.

Pixelight
04-28-2011, 07:54 AM
To help you a bit Pixelight... the luminosity does need to be very high to get a visible effect... around the 1000% mark will show some light, depending on the scale of your scene.

Also, when you get into adding the Radiosity, I've found that reducing the 'Multiplier' at the bottom of the Radiosity panel to 50% will make a cleaner solution around corners etc. This acts as the resolution of the Radiosity solution... so 50% means that the solution will be half the size of the camera resolution. This can smooth out a solution a bit, and make it look nicer.

Thanks. I tried it that way by using luminosity and it didn't work. But I didn't try anything too high. I will try bumping it up as you suggested. But is this a better way than using luxigons?

Pixelight
04-28-2011, 07:56 AM
I guess unless the OP comes back and clarifies *exactly* what he wanted, we could go on about his forever.
My assertion, however, and I think I'm right, is that he wanted an object to behave as if it were a ray-trace light. Not with GI, but like a point light or an area light is.
My answer was not wrong, considering the above. If I misunderstood him that's one thing, but I don't think I did.


What I'm trying to do is a neon sign to cast realistic light and shadows on objects around it. I don't much care the method through which this is achieved or if it's faked or not as long as it looks realistic. Like a real neon sign on a building facade would illuminate and cast shadows on the wall behind it, on the metal structure frame holding it etc.

rcallicotte
04-28-2011, 07:57 AM
Pixelight, maybe this will shine some light on the subject -

ftp://ftp.newtek.com/multimedia/movies/LW_9/NeonText.mov

Pixelight
04-28-2011, 08:05 AM
Pixelight, maybe this will shine some light on the subject -

ftp://ftp.newtek.com/multimedia/movies/LW_9/NeonText.mov

I actually have already watched that video even before posting my question. But it only talks about making it look like neon but not actually about how to make it behave like neon, meaning sending out illumination etc. I need a photo realistic look.

lardbros
04-28-2011, 08:27 AM
What I'm trying to do is a neon sign to cast realistic light and shadows on objects around it. I don't much care the method through which this is achieved or if it's faked or not as long as it looks realistic. Like a real neon sign on a building facade would illuminate and cast shadows on the wall behind it, on the metal structure frame holding it etc.

Fair enough... sorry to keep on IMI... I realise you suggested it first. I guess I personally think that there isn't much difference between using an area light or using a luminous polygon. Rendertimes are clearly different, and you need GI... BUUUUUT aaaaaanyway, onto the solving the problem.

I still think the best option is to use luminous polys. Obviously there are down-sides to both this and the luxigon method.

With the luminous polys, you have to have Radiosity on, which will suck up your render time. Although on a relatively modest system it should be fine really.

The luxigon method could be nice, but depending on the lights you use, you won't get nice soft shadows, but if you use many area lights this will sap your render time as much as the Radiosity.


From your description, I'd use the Luminous polygons. It would definitely have the most photoreal look, if that's what you're wanting. Although, I'm sure the DP light plugin would work too... and it is free. All of his plugins are. The gotchas are: Make sure you have radiosity on, also make sure you have the luminous object cranked up high enough!! Try a crazy % first, and see if it has any effect.


(IMI, kiss and make-up? :) Sorry to have aggrevated you in any way)

rcallicotte
04-28-2011, 08:50 AM
Then I would consider finding a way to implement radiosity with GI with maybe a solution like this. Hence the ability for other objects, like luxigons, to help light up the atmosphere.

Where is Nicholas Boughen when you need him? :lwicon:


I actually have already watched that video even before posting my question. But it only talks about making it look like neon but not actually about how to make it behave like neon, meaning sending out illumination etc. I need a photo realistic look.

masterchief
04-28-2011, 09:11 AM
Jeez, Oliver - chill, no need to get sarcastic and condescending.


Reread your posts, #3 and #7 .. all people are really interested in is if you can help solve a problem when they ask specific questions. people will be less abrasive if we all try to remember that. peace

masterchief
04-28-2011, 09:14 AM
'To err is human ...'

HEY STEVE! I do that all the time. I am very human. LOL

How have you been?

William

masterchief
04-28-2011, 09:29 AM
Short answer is, you can't. The closest you can get to it is to make it ambient and glowing and use GI. With GI or Final Gather, all ambient surfaces will contribute to the lighting in a scene.
But unless there's some plugin for it somewhere, you can't actually make an object a light in LW.

LW 6.0 introduced radiosity to the lighting toolset, giving artists ability to create custom lights in any shape they wished. Radiosity is actually based upon surfaces, not objects, but that provides you greater flexibility.

Any surface with a luminosity value will emit illumination into the scene if you have radiosity turned on. The trade-off is that radiosity can be a painfully long render. But used judiciously, this can still be an invaluable tool in your search for photo-real perfection. (quoted from Lightwave 3D 8 Lighting, Chapt7, Objects as Lights, page 102, first paragraph...Nicholas Boughen ISBN 1-55622-094-4)

... afterall, yes this is Lightwave you know. LOL

JeffrySG
04-28-2011, 11:50 AM
JeffrySG that looks great!
I did sort of know that scenes could be lit with luminous objects but I didn't know that they could be lit without lights.
Thank you :)

As reference, what percentage/ brightness were the luminous objects?

It was a while ago so I don't remember what percentage of luminosity those materials had but the bright ones were probably around 300-600%. Also the GI intensity % will have a large effect on the entire scene when using luminous polys to light your scene. This is where having fPrime or LW10 with VPR will really help. For that scene I just did a bunch of tests with low quality GI settings. Then ramped them up a bit for this one that I posted.

edit: also it's a good idea to turn your ambient light down to 0% for these scenes. At least I've found this to be true for my projects. Thanks too. :)

GraphXs
04-28-2011, 03:55 PM
I attached a sample on how i would make the Neon Glow FX.

Things I do:

-I do use Radosity
- I use 2 objects
1 object is the neon light tube
1 object is the Luminous tube with a high Luminosity value for the surface, and also hidden by the camera, but seen by rays under object properties.

That's it!:thumbsup::D:lwicon:

Ya can control the bleed/intensity of the luminous polys by upping the luminosity.

GraphXs
04-28-2011, 03:57 PM
image sample

Pixelight
04-28-2011, 05:10 PM
I attached a sample on how i would make the Neon Glow FX.

Things I do:

-I do use Radosity
- I use 2 objects
1 object is the neon light tube
1 object is the Luminous tube with a high Luminosity value for the surface, and also hidden by the camera, but seen by rays under object properties.

That's it!:thumbsup::D:lwicon:

Ya can control the bleed/intensity of the luminous polys by upping the luminosity.

Hey, thanks for taking the time to do that.

Pixelight
04-28-2011, 05:11 PM
Thanks for all the replies guys. Truly appreciated. I will give the radiosity with GI a go. But I would still like to know if it's not possible to apply luxigons on text faces?

Tobian
04-28-2011, 06:03 PM
Pixelight - the luxigons are *just* placed lights, so they are never going to turn into light emitting polygons, it's just a handy tool for placing something on a polygon. I suspect the problem with the text is it's a dense ngon, and the plugin might only support quads. the answer would be to break the text face down into quads, but even then, it's still going to have the problem of not looking light a light-emitting polgyon mesh. You may get that feature to work, it just might not do what you expect or want it to do.

The DP light emitting polygon plugin (which is free to download btw!) will do what you want, though it can be quite slow, if you have a lot of luminous geometry in a scene. you still need to resolve the appearance of the geometry which wil involve lots of messing on with the surface editor and or the node editor :)

The luminous geometry could be the way to go, though with radiosity getting the settings in the sweet spot for speed can be a dark art at best :D (and this is the same for any app, which is why many implement polygon lights) However it is quite possible to get very good and fast results out of LW if you do get it right.

I also don't use the same approach as GraphXs as I tend to surface and have the illumination be at the same level for the geometry, but that's because I a)have figured out how to get the luminous surfaces to look right, with tone mapping, after the render is done, and b) if the luminous element doesn't match it's radiosity counterpart, you can end up with weird issues with reflective or refractive surfaces. That and if you use a modern Linear colour workflow, you will get much more realistic and pleasant light falloffs and more 'light' in general from weaker less luminous lights. As a rule of thumb though don't use values much over 1000% bright, as it will start to freak out the radiosity engine, without special care to disclude it or partially disclude it, but that comes into the high-end realms of nodal surface tricks.

As an example http://comby.star-fleet.org/test161.jpg and http://comby.star-fleet.org/test158.jpg were lit entirely by radiosity, there's no active lights in the scene, just reflections and radiosity, so it's quite possible, just tricky :D

Scazzino
04-28-2011, 07:32 PM
Luxigons are really just placeholders. They are just recording the position and orientation in Modeler to make placing a regular light in Layout easier.

GraphXs
04-28-2011, 07:54 PM
Great work Tobian, your 3D world article is amazing by the way! The only reason I have the Luminous over the neon mesh is because I don't want the neon mesh to get blown out and want to be able to control it's color or texture with more control. I found doing this for some models help give me a glow falloff/bleed while still maintaing the look/detail of the model. One thing I will probably add to the neon is just a post glow falloff to the mesh to give it a softer edge around the model.

I'm not sure I understand your tonemapping process, can you explain it more. In your images it looks like you are just using the high luminos white polys to be your light. I'm assuming that you are using them at a high precent. I'm also assuming the use of relections will bounce that light around more when you use GI. Is their a magic number for the GI setting vs high Luminous polys that need to take into account? Are you also just using normal reflection bluring, or is it node based?

Thanks!

Snosrap
04-28-2011, 10:47 PM
Floor lit by TV screen. Just add luminosity to your surface and render using GI.

IMI
04-29-2011, 04:59 AM
LW 6.0 introduced radiosity to the lighting toolset, giving artists ability to create custom lights in any shape they wished. Radiosity is actually based upon surfaces, not objects, but that provides you greater flexibility.

Any surface with a luminosity value will emit illumination into the scene if you have radiosity turned on. The trade-off is that radiosity can be a painfully long render. But used judiciously, this can still be an invaluable tool in your search for photo-real perfection. (quoted from Lightwave 3D 8 Lighting, Chapt7, Objects as Lights, page 102, first paragraph...Nicholas Boughen ISBN 1-55622-094-4)

... afterall, yes this is Lightwave you know. LOL

I was going to forget about this thread but I can't help myself. :D
Man, did you even read the stuff I wrote? It doesn't look like you did, based on the above. How many times do I have to write that I was going on the premise he wanted an actual ray-trace light in the form of an object, not a luminous object with GI.
How many times do I have to write that? The half-dozen or so times I already did weren't enough?
Maybe I should have put it into my signature line as well?

To the OP:
I hope you've gotten enough useful information from this thread in order to achieve what you're wanting to do, and I'm sorry for causing it to get derailed by the unnecessary stuff I added to it.