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Jamo3D
08-25-2003, 10:44 AM
Hi there,

I read in an old article from CGChannel about how TMPC used Shake to do all their lighting for the whomping willow scene in the 2nd Harry Potter movie. What they did was render scenes with no lights and output surface normal data per pixel from PRMan and fed it into a custom plugin in Shake. Where their renders used to take up to four hours per frame, with this system, they were doing lighting in near realtime.

My question is, what other (cheaper and without a custom plugin) options are out there for doing this? I would've thought Max and Combustion since discreet make a big deal of how they're integrated but I have no idea about the PC side of things. My other candidate would've been Cinema 4D and AE but AE's 3D isn't mature enough to do this yet. No idea if the AE plugin for Cinema 4D works with Combustion. Any ideas?

Jamo
+BIL

comanche
08-25-2003, 11:12 AM
Well, with Cinema4D, the easiest way would be to render out separate light passes (see the options in the light properties and multipass settings). You can't change position and type of light afterwards in post, but you have control over the lights diffusion, specular and shadow. This way you can even render out different lighting situations with one single rendering, and tweek everything in post.

I can't help you with the normal map question though.

Cheers,
Andreas

Jayk2k
08-25-2003, 03:49 PM
If you output RLA or RPF files from your 3d app of choice with normal information in them, DF and DFX+ have a Shader node. That will allow you to add lighting to the object.

Realisticly though, I don't think it would work as well as a final rendering in 3D. The DF tool itself is relatively basic. Might be worth a try though.

Blur1
08-25-2003, 04:39 PM
I am going to try and work out a way of doing this in AE with expressions. I'm pretty sure it's just simple trigonometry, where the relationship to be established is based on the angle of a 3D light in AE, the brightness value of each channel in the normal map and the RGB mix of the light's colour.
Don't know when I'm going to have time though.

You might also want to look at this:

http://grabiller.3dvf.net/site/content/art_fxtree_parser_eng.html

LW3D
08-25-2003, 05:25 PM
I think, same feature (relighting rendered picture in compositing) is built in feature of Houdini Halo. I have seen a video which shows how this can be possible using Deep Raster Images in Halo. Check sidefx's educational videos for Halo..

Also somebody said that, Tippet Studios showed same techniques in Siggraph 2003, using Shake.

Aruna
08-25-2003, 07:46 PM
Yes.. We have an inhouse lighting tool that allows us to light objects in shake using a normals render from Maya. One of our lead 2D artists demonstrated it down at Siggraph this year. We can change spec, diffuse, and color values, as well as the type of illumination (spot light, directional light, etc)

I think Combustion and MAX have the ability to relight objects using their proprietary RPF format, with each surface or object having a separate object ID. I am not familiar with Combustion to really comment more than that!

Jamo3D
08-26-2003, 09:35 AM
Originally posted by Aruna
Yes.. We have an inhouse lighting tool that allows us to light objects in shake using a normals render from Maya. One of our lead 2D artists demonstrated it down at Siggraph this year. We can change spec, diffuse, and color values, as well as the type of illumination (spot light, directional light, etc)

I think Combustion and MAX have the ability to relight objects using their proprietary RPF format, with each surface or object having a separate object ID. I am not familiar with Combustion to really comment more than that!

That's great! I have a buttload of questions to ask you then.:beer:

How well does it behave with reflections?

How well does it behave with caustics and other distortions?

How well does it behave with shadows?

How well does it behave with occlusions?

How well does it behave with translucency?

How well does it behave with complex lighting and shadow and an 'all of the above and more' scene?

Do you have a gallery or a reel using this method? btw - have you tried this with Flame? The blurb from discreet says it reads and writes lighting, camera, animation and object data from Maya, Houdini, XSI and even Lightwave files.

Thanks!

Jamo
+BIL

Aruna
08-26-2003, 04:44 PM
Well, since it's just a 3D to 2D trick to achieve lighting, all your other points that you mentioned; reflections, shadows, occlusion, translucency and transparency, can be achieved through the compositing interface. It's not an all in one solution, but used correctly, can give you quite a bit of the below results when paired with several different render passes from 3D (normals, ambient occlusion, reflection, Z-depth, etc). Since you can render out any number of different types of passes through Maya, you 'll be able to fake a rim light on an object in 3D in 2D in shake. Since it is just a 2D tool and program, there are no provisions to provide caustics and reflection/refraction of light. That would be much better suited to wholly 3D! Creating caustics and refraction can be more easily done just using compositing, that trying to achieve accurate refraction with a 2D lighting tool!

I personally don't have a gallery or reel that contains these examples.. Several of Tippett's more recent work contains 2D lighting elements. From what I remember being told, Blade 2 had it, and I think Hollowman may have as well. We're currently using it quite a bit for Revolutions.

I have done limited lighting in flame, and it
can do colored lighting, spot lighting, etc. Don't expect to get radiosity renders or raytraced renders out of it, but again, just like in shake, if used correctly with other types of passes, you can create something that looks like it was actually lit that way. There are some rudimentary plugins for discreet FFI that allow the creation of geometry to cast shadows and light. And since it is a true 3D compositing environment, you'll have a better chance or accurately creating true lighting.

But I'm a comper.. I specialize in faking reality any way possible. :)


Originally posted by Jamo3D
That's great! I have a buttload of questions to ask you then.:beer:

How well does it behave with reflections?

How well does it behave with caustics and other distortions?

How well does it behave with shadows?

How well does it behave with occlusions?

How well does it behave with translucency?

How well does it behave with complex lighting and shadow and an 'all of the above and more' scene?

Do you have a gallery or a reel using this method? btw - have you tried this with Flame? The blurb from discreet says it reads and writes lighting, camera, animation and object data from Maya, Houdini, XSI and even Lightwave files.

Thanks!

Jamo
+BIL

Jamo3D
08-26-2003, 05:29 PM
Originally posted by Aruna
Well, since it's just a 3D to 2D trick to achieve lighting, all your other points that you mentioned; reflections, shadows, occlusion, translucency and transparency, can be achieved through the compositing interface. It's not an all in one solution, but used correctly, can give you quite a bit of the below results when paired with several different render passes from 3D (normals, ambient occlusion, reflection, Z-depth, etc).

Do you guys have any plans of releasing this commercially or collaborating with someone to release it commercially? Ideally, Apple would include that as a recognised and supported technique for using Shake with 3D, but if you guys release some plug-ins before that then hey!

I look at this as a 'next big thing'. One of those buzzwords that everybody wants their 3D and FX suite to have support for. But the technique doesn't even have a name yet. I hereby christen it COMPOSITOR LIGHTING (tm). You saw it here first. I didn't invent it, just named it.

Jamo
+BIL

Cogliostros
08-27-2003, 02:28 PM
aruna,

comper rule.

;)

Aruna
08-27-2003, 04:52 PM
Jamo3D: I am not in sales, and Tippett is not into selling its software. It would be too much of a hassle, since we are in the business of making visual effects, not selling software. I'm sure some entrepreneurial wizard will eventually sell a plugin. I mean, Nuke has it already, and it's built into the software.

Cog: Wicked. ;) How's the show treating ya?

beaker
08-27-2003, 08:29 PM
Originally posted by Aruna
Jamo3D: I am not in sales, and Tippett is not into selling its software. It would be too much of a hassle, since we are in the business of making visual effects, not selling software. I'm sure some entrepreneurial wizard will eventually sell a plugin. I mean, Nuke has it already, and it's built into the software.

Cog: Wicked. ;) How's the show treating ya?

Yea, but Nuke took how long to become a commercial product? 10 years. Scott Ross (DD CEO) has been talking about commercializing Nuke for atleast 5 years if you go back and search the newsgroups on his posts. The problem doesnt have to do with selling it, but supporting it and writing documentation. Thats a huge task within itself that is a pain in the ass. You then have to balance the feature requests and bug fixes of your customers with your internal staff ones. It's alot of work and not everyone is interested in that market.

dmeyer
08-28-2003, 01:53 AM
Originally posted by Aruna
Jamo3D: I am not in sales, and Tippett is not into selling its software. It would be too much of a hassle, since we are in the business of making visual effects, not selling software. I'm sure some entrepreneurial wizard will eventually sell a plugin. I mean, Nuke has it already, and it's built into the software.


How about licensing it to someone like GenArts? ;)

LW3D
08-28-2003, 08:20 AM
Actually I don't think Nuke has this feature built in. 3D compositing/lighting and relighting rendered picture using normals are too different approach.

I think only Houdini Halo has this feature. Following videos showing how do you use normals and relight rendering picture in Halo (not using 3D lighting/compositing feature). I hope this help to understand technique.

http://www.vislab.usyd.edu.au/sidefx/houdini_video/video_data/divx/compositing/lighting_01.avi 5.4 MB

http://www.vislab.usyd.edu.au/sidefx/houdini_video/video_data/divx/compositing/lighting_02.avi 5.8 MB

best regards

Gokhan

Aruna
08-28-2003, 04:41 PM
See this thread (http://www.vfxtalk.com/forum/showthread.php?s=&threadid=845) at VFXtalk.com. It does have lighting in a true 3D compositing environment.

In this case, I don't think NUKE would use a normals pass to render lighting, instead relying on true geometry.

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