Light Linking
Dartanbeck
Posts: 21,549
This thread can be easily ignored if you already have a good grasp of how to get your lighting set up to produce your vision in your render.
It is dedicated to help to show some examples and explanations - eventually some diagrams and screen shots - of how we can use simplicity in Light Design to help get the point across the way you really want it - to make your rendered images turn out the way You want them to.
Hollywood directors and their camera people don't add extra lights and tweaks to scenes that already have natural lighting to try to mimic reality. They do so to accentuate the important parts of the frame, set the right mood, give the viewer the sense and feeling that the director needs them to. Photographers often use the same techniques. Then still, using similar ideas or inventing new ones, some people even endeavor to push beyond the norm and go for something altogether new.In 3D rendering software, we have many amazing advantages that surpass what can be achieved in film - we can "Link Lights".
So this thread is not about how to use Global Illumination with Indirect Lighting to have the software calculate true realism automatically - nor is it endeavoring to dismiss it. Later, we may even get into some of those techniques to help illustrate differences or even hint at some good practices to think about when using them. This thread is more about creating your own Light Designs to help you gain a higher level of control over the whole scene. These designs can be used to create something that looks very realistic or can push deep into something vastly more fantastical or horrific or something else entirely.
Why?
Why should we take the time to design a lighting scheme when our software has all of these options to do the hard work for us?
Allow me to ask some questions to help lead us toward the most obvious answer to this question:Have you ever had shadows show up where you really don't want them? Perhaps they are blocking or otherwise messing up the main focal point of the scene?Have you ever spent a great deal of time on shaders that should get the light to create certain effects only to find that it isn't working as you were expecting them to?
Have you ever had your scene render turn out just perfect until you add the rest of the elements essential to the final image because, once added, they change the shadows or other aspects of the lighting?
There are many other situations that occur when using automatic lighting solutions that can be easily fixed by Light Linking and/or other techniques that stray beyond the automatic.
Take space scenes for example. How do we use natural light in space? You add elements to the scene that realistically (or otherwise) believably add light sources to the scene so that we're not seeing the unlit blackness of an object block the lit stars beyond.
When we "Design Lighting" it is always a good idea to remain believable. In that, I'm talking about making sure that: Where there is light shining onto an object, make sure that there is some kind of reason for that light to actually exist, or it can (and will) look fake. Before we get into that subject too much, I'd just like to mention that this is incredible simple to do, so try not to over-think it too much. Sometimes it can be fine to simply ignore this idea entirely, if you know it will work just fine - or when you feel that it's important to leave the 'sense' out of the equation altogether for sake of your artistic needs. In short, it's super easy to add an object that appears as if it could, should, and would cast light. This is Carrara, where we can make anything that we want, glow!
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Light Linking
Linking a light is the act of having it affect one or more objects, but not the rest. The reverse is also a "Link Against". If we say we need to link this light against the car, that means that we make the light affect everything in the scene except for the car, on which it has no affect at all - not even shadows. Likewise, if you have a car on a road, and link a light to the car and not the road, that light will not cast shadows from the car onto the road.
When we look at it like that, we should immediately see that we rarely want to use only linked lights. We'll almost always want lights that affect everything in the scene for shadows sake - but not always.The first sentence in this section uses "one or more objects" in it for good reason. Sometimes, for shadows sake, we'll want to include several objects in the link - say, the car and the road, as an example. Next it talks about linking against, which can be incredibly handy for using Distant Lights while also using something in the scene that surrounds everything, which would also block all light from that distant light from being seen in the camera's view at all. Distant lights can be enormously handy when you have many objects or angles in the scene that all need to have the same light coming in from the same direction at the same strength. But if you're inside a surrounding building model (as an example) the building walls, floors, and ceiling, etc., will make a solid shadow from the light, effectively preventing any light from a distant light from coming through. As an alternative, it's quite common to use spot lights and duplicate them all around the inside of the building, which is fine. But using Light Linking, we can Link Against the building and anything else that may block the way, and then just add a select few spot lights where needed for shadows being cast onto what is being linked against. Follow me?
That might be getting a bit heavy for a start, and I didn't really intend to get that deep right away... so if it's not all soaking in just yet, don't worry. I'll tackle all of that stuff as we go.
It's kind of strange that I'm starting this thread right now, because I have been very, very short on time lately. So this is actually also an attempt to make a solid return from being so very away from both Carrara and the Community for such a seemingly long time. So let's get an example going, shall we?
Yesterday was my first stab at breaking back into Carrara and it didn't go as well as I had originally intended. Getting sub-zero temperatures gave me nearly the whole day's worth of extra chores, but I ended up busting through those and, between midnight and 2:30 AM, I was finally able to play! But what will I render? I pulled out my Rosie and Dartan characters, put a glowing artifact in Dartan's hand, gave him an expression of confused wonder, while Rosie looked on cautiously... protectively. The render would have turned out great, and it would have been an excellent way to demonstrate Light Linking. But when I looked at it, it was just too similar to so many of my other Dartan and Rosie renders that I decided to close without saving, and pick a new subject.
With some of my friends, this Starship (Cyclone) raised a bit of controversy over how similar it looks to a very famous craft of the late seventies and into the eighties. Well... perhaps even a bit closer than "similar". Nonetheless, I think it's a really cool model, so I loaded in Starry Sky for Carrara, dropped in the Starship: Cyclone, optimized it's shaders and gave it some lighting and a dramatic pose. Then I dropped in Star Ship Piranha and twist some of it's parts about in impossible ways and brought in the rocket engine emission particle emitter from Chapter 10 or 11 from Phil Wilkes' "Advanced Carrara Techniques" (by Infinite Skills) working files and tweaked some of the emitter settings and the shader a bit to meet my requirements.
This thing works so well for an instant explosion, burning something or other... I get a lot of use from this crazy emitter working file!
Being in Space, Distant Lights can work like a charm! Hmmm... after I added in the second, blown away ship and the particles, my Rim Light (bright light coming in from behind as a "pop" light - accenting shape against the dark) was being partially blocked - adding shadows to my Cyclone (foreground ship). I also have a new element in the scene that casts light - an explosion!I linked the original Rim light to the Cyclone, then duplicated it, changed the angle, changed the color to bright orange-yellow to simulate it coming from the flames. Since I've duplicated it, the new one was still linked to the Cyclone, so the only light on the victim ship were from the front Fill and Key lights, which were also Distant Lights from the original setup I've put onto the Cyclone.
So now all I had to do was to duplicate the Rim light and the new Orange-Yellow effect light, change the link to the other ship, and angle them correctly for the proper effect!
Distant Lights
Something that "I" love about using Distant Lights, when I can, is that I can bring them into view of my render camera and just focus on the direction of the light, not on the exact placement. I can then set up whether the shadows need to be soft and, if so, how much, set the brightness and color... using light linking can really help distant lights to become vastly more useful than they would be otherwise. Granted, other lights have other settings and advantages over these for certain shots. We'll cover those other lights very soon.
I rendered it out, brought it into Howler and added some motion blur and highlights to some of the lights and stars... and here we have our first example. I'll expand this subject more very soon.
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Comments
the above is the first post in a new educational series being offered in the ►►► Carrara Information Manual ◄◄◄
The series is called Adventures in Lighting, and hopes to become yet another massive, crazy endeavor in the hopes that we can all learn, grow, and share together.
Cheers and Happy New Year! May 2015 be another grand year for Carrara and those of us who use it! :ahhh:
Dartanbeck
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Subject Index
► Homework #1 - Two Videos to Watch
- Light and Shadow - Greatest Cinematographers of the World, Interviewed
- Paint with Shadows - An exercise in Global Illumination
► Dartan & Rosie - Badlands Cave Passage Demonstration
" I brought it into Howler and added some motion blur and highlights to some of the lights and stars…"
Shame on you Mr DartAnbeck !!
but a damned nice image all the same ;-)
and your manual is so indispensable we purists have to forgive you.
I have so included Howler into my Carrara endeavors that I almost consider the two to be one... so I'm feeling no shame!
The thing is, just about everything I do in Carrara is an animation. So I'm trying to instill some of the actual motion into my solitary images to help illustrate that it's just a part of a larger thing... if you see what I mean ;)
:)
...and thank you for the fine compliments, my friend! I'm also hoping to get some activity going in the CarraraTors forums as well. After all, Carrara Animation is my thing all along... that's all I ever want to do! So you'll be seeing some animation goodness as soon as I can break the speed of time... :ahhh: which should be soon! ;)
Juist having a dig as I'm sure you realise :cheese:
A perfect way for you to introduce your work to CarraraTors would be to enter the "My Mini Movie "competition.
Edit add link http://www.daz3d.com/forums/discussion/50895/#743007
A requirement is that producer submits a comprehensive description with the entry of how the animation/movie was created - tools techniques plugins used etc -a tutorial in itself BUT no post processing with Dogwaffle or anything else !!! ;-)
That will leave me out. Animation and video is all about post processing. There are effects such as motion blur or DOF that can be done more quickly and efficiently than in Carrara. Then there is compositing which saves so much time and allows much more freedom....
The Challenge WIP threads are a great way to learn some these tricks as well.
http://www.daz3d.com/forums/discussion/45254/
Here's one where I discuss light linking:
http://www.daz3d.com/forums/discussion/47148/P330/#696563
This one has a handy graphic!
http://www.daz3d.com/forums/discussion/33911/P75/#507605
I'm almost in the same boat. I bought Howler specifically for assisting with my movie process.
I may just enter that for the mere joy of it. But more so, I am also kicking around ideas for something sweet - as I'd like to (not positive yet, so nothing official just yet, okay?) up the ante on the winning prize(s). This sort of practice, education, cooperation, and thrill of pulling off something awesome in Carrara is exactly what I stand for... it's one of my favorite things in the world to do.
I'm not sure if my next product that I'm producing for DAZ 3D is quite appropriate for an animation contest prize (except that all of my products are designed to enhance animation endeavors), I'm thinking up ideas for something a little more exclusive - which may become another DAZ 3D product as well. We'll see, and I'll keep you posted.
I'm going to be honest, I've looked at Howler several times and I have no doubt it's great at what it does based on your many comments Dart, but I honestly can't puzzle out what it does exactly, except that it's sort of the same as After Effects, which doesn't help me much because I have no idea what After Effects does either, or why programs of this type are so important in information...
I feel like it's one of those things that I'm going to need when I start getting more into animation, but I have no idea why I need it. In fairness that's the same reasoning for Fenric's ERC; I purchased it thinking that as I get more advanced in understanding Carrara I will one day find it absolutely invaluable, but for now I have no idea how to use it... :)
I can't speak to Doogie Howser...I mean, Dogwaffle Howler...since I'm not familiar with it. Though I believe it's basically a 2D painting and motion graphics application. Which pretty much means you paint some really cool and complicated stuff in 2D, and you can animate it...kind like the Simpsons... :) ....Just joking.
As far as After Effects, it does some of the most important stuff in filmmaking. Y'know how in music they use tracks? Like they'll record the drummer on one track, and then the singers on another track, maybe even on a different day and different location, and so on. And when it's done they bring all the tracks together, and voila, you have an entire song that was produced in layers. Then you can go in and modify, say, the guitar and give it some cool sound effects it didn't have when you recorded it initially. And you can experiment, maybe add some reverb or change the volume, and so on.
The same principle applies to making films. You can hire some very high priced actors and have them do their acting in a small, controlled room, record it, and then later place them in the middle of this incredible city scene with monsters and explosions and stuff all around them and it looks real. And you didn't even have to hire any monsters.... :)
After Effects, and software like it, allows you to do what's called "compositing", which is when you film actors, and have guys generating 3D cities in 3D software like Carrara (but different), and other guys generating sound effects, and other guys generating explosions and smoke, and other guys making 3D spaceships....and when all the layers are done, everyone gets together and puts their layer into After Effects (or similar) and it composites them all together into a single motion picture. It's an EXTREMELY important aspect of filmmaking. It's called "post production" because it's all the stuff you do after you've produced the film of the actors, etc., and you put it all together and edit it into a single film.
Here's a nice video that ILM did to showcase some of the post work that they did in Avengers. In many cases they just filmed the actors in a small room, and they had to act and react as if there were monsters and stuff blowing up all around them, because they would later be composited into a big exploding city scene. It's cool stuff. And this compositing is just one aspect of special effects and postwork.
https://www.youtube.com/watch?v=MnQLjZSX7xM
Evilproducer/Dartanbeck - you are of course absolutely right in terms of an end product (movie) - achieving things with post processing not possible or that just take too long to render in Carrara.
But the Animation competition is about "using" Carrara and to show what you can do with Carrara .
Or another way to put it is show what clever things Carrara can do rather than what clever things other software can do..
I've already mentioned above somewhere that for some it can be a learning process because they attempt things no previously tried.This maybe a bit boring for old experienced hands but we would still love to see you participate. :coolsmile:
Yes - we know what green/blue screen and compositing can do for movies and here is a really good illustration https://www.youtube.com/watch?v=WB4H774bmbI but we are not looking for this sort of blockbuster [ YET ] !
Well, apparently not everybody... :)
I was merely replying to Jonstarks statements that he didn't understand what After Effects is....sorry if it wasn't helpful.
Thanks Joe, that does help to explain it a little. I can see how compositing would be an important part of filmmaking, did not realize this is what After Effects did before.
...and I'm glad you've asked, Jon. This is an excellent topic to discuss. When we bring in Backgrounds or Backdrops, images or videos on a plane, etc., it can all be thought of as a form of compositing. I have done multiple composites within Carrara using nothing but Carrara. In my first few years of using Carrara, I was hell-bent on NOT using any post effects beyond the Movie software for stitching my clips together, relying only on Carrara to do everything. So I would set up a scene with all elements in it, hiding much of it as I went to save on working view as well as render times. Then I would start from the most distant elements, using the final motion camera, and render just those. Then bring them in as the Backdrop and remove them from the scene. Make the next batch of items visible and render again, and so forth.
There are times when fog, fire, volumetric clouds, and other Carrara effects, might render improperly along with transparency maps, as an example. Now, instead of not using them together, I'll simply render them in layers. In doing so, I'll use some of those effects behind the character (or whatever) and then some in front. But render them separately, on top of one another in Carrara instead of using blue screen techniques.
However, Howler uses blue screen, green screen, and drop magenta or magic pink, in its layer system. So you can actually render using these techniques in Carrara, or even shoot video footage as such, and use Howler to composite.
With Carrara we can render with Alpha. So we can omit the screen altogether for a nice, pure animated brush in Howler. For animated Alpha, we need to use sequenced image files instead of a movie package, like avi - at least at the time of this writing.
Howler uses brushes for this, instead of layers. So we would load the Alpha image sequence into a brush and store it. Repeat for as many elements as you need to work with. Load in your background avi or sequence and use the individual brushes to complete the composite. Each individual element (video brush) can be moved, scaled, made more or less transparent, or just about any other image edit you can think of, directly onto the current background video.
I also enjoy using Howler for a simpler and much faster motion (or any other) blur onto my animation. This way I can set an animated selection of where the blur is to occur, and animate the blur itself - while saving a LOT of time, in the process - just as a quick example of why else I have become so attached to using Howler with my Carrara stuff.
Joe,
Thanks for the cool explanation and link.
Here's another short of the same ILM work on that movie, explaining a bit about it:
https://www.youtube.com/watch?v=2ZsEwUuBjio
For anyone with a bit more time to watch, try this one on for size, speaking of ILM: ILM: Creating the Impossible (one hour documentary
I probably shouldn't have said "we all know" [ about green screens ] so apologies.
A few years ago I had the opportunity to observe first hand during local filming of the 3rd "Narnia" movie.
Her a couple of shots I took of the set for the "Dawn Treader "
In the first you can see the back of a massive blue screen suspended from a crane.
Second shot shows the life size "Dawn Treader " that took 3 months to build - never got it's bottom wet once being mounted on massive turntable which enabled it to rock n roll.The wild seas were of course added later. Note camera platform suspended above deck.
The video clip shows some scenes from the movie itself and some great animation added with the help of the blue screen.
https://www.youtube.com/watch?v=sfcFwH0J_3I
and this one because I love the cute little rat.
https://www.youtube.com/watch?v=9iuetrhn2y0
Just thought you might be interested to see.
Dart - what about adding your green screen thoughts to The CarrarTor forum under "movie making "
I might not be the best person to speak about green screen and the like, as I make everything in 3D, so I have no need for it yet. I could, however, discuss many other things that I've worked out on my voyage as a Carrara animator.
Soon I do hope to get over there and introduce myself among the forum there.
My apologies. I think I'm the one who derailed it... :red:
My apologies. I think I'm the one who derailed it... :red:
............and the Dart extended it ;-)
Not a big deal - it all fits in one way or another anyways.
Wow, are those some cool photos Double O!
I really like those Narnia movies. That must have been a cool experience to actually run around on scene like that!
Homework: Watch Light and Shadow -- Greatest Cinematographers of the World, Interviewed.
Paint with Shadows – An exercise in Global Illumination
So here I use EnvironKit - Badlands as an example. Each EnvironKit scene comes with a Light Linking setup built right in. It's called "Focus Group - Add your Main Objects Here". It's purpose is to provide an instant method to make anything you might bring into the scene "Pop", or... give it some added attention through Light Linking. So inside the group is another group containing the Focal-Point Light Rig.
Now, the way I save my characters is that I optimize their shaders, give them all of their equipment, for instance; Dartan's sword on his back is visible in the sheath by default but there's an identical one parented to his right hand, which is not visible by default. I have also saved an animation file where he unsheathes his sword - the one on his back disappears the frame that the one in his hand appears - as he draws it in earnest from his back! Sweet... yes?
More importantly for my incredible lack of time, each character also contains their own light rig linked only to them. When I bring them into complicated scenes, the only drawback is that the lights may become linked to the wrong thing through the loading process. Being aware of this, I simply go through them and very easily set them back to link to the correct thing - the specific character, or a part of him or her.
this is incredibly handy because it allows me the freedom to light my scenes for the scene, and not for the characters, except for very few circumstances. But all in all, the setup saves me a lot of time.
So for this example, I've opened up the default Cave Passage scene from the Realistic Sky category of Badlands.
Being in Carrara 8.5, it loaded up into the default Director's Camera. C8.5 is the first version to allow for this behavior - and I like it!
So now I load in both Dartan M4 and Rosie V4 from the browser. Leaving them in their default arrangements, I take them in turn and 'Align' them to Film Cam 1. Since they're both directly on the camera now, I pull Dartan back away from Rosie, switch to Film Cam 1 and back it off to center them into the production frame. This isn't an animation, so I do away with the widescreen angle, and center them up again. I give them each an expression and very slightly alter their default poses which I've saved them in. I like to save my Heroes into a good, default, ready-to-render pose. I check that all of the character's linked lights are linked correctly, but for this example, I just wanted to illustrate how well their default situations work in this quick and simply setup.
Without adding the heroes to the "Focus Group", I shoot a render just using their own rigs without even taking any time to adjust them for the scene. Here's what I got:
Still not changing anything, I've dragged the two hero groups into the "Focus Group - Add your Main Objects Here" group, and got this:
Ooops, I've accidentally hit "Render" before saving! LOL
No big deal for this quick demonstration! :ahhh:
here's a screen shot with a quick glance at part of my Carrara Hero setup.
Notice the browser panel to the left.
Each category in my custom browser really opens up and becomes an immense time-saver towards keeping things like:
- Animated expressions and moods
- Saved Animation setups that can be reused for many scenes
- Character Saves wearing different clothes, different shaders, using different lights, animated hair....
- Optimized Clothing - this category opens into a large organized closet of everything I have optimized for the particular character
...and that's just showing the "Rosie 4" category!
Now take a look at wear the manipulator is. Right behind her nose. This is a tiny target helper, which all of the lights from her custom rig point at, and are parented to. I used to have this parented to her hip, but that has created some unnatural lighting situations - I just didn't like that. So now I simply include it into her group and set the position of the target helper for the animation at hand. Very easy and produces very nice, consistent results. They are fairly subtle lights, but you can see above that they make a huge difference!
Suffice to say that, for the actual action scenes, I take extra time and aim the lights from their individual rigs to match what I'm doing and it turns out really well... at least I think so.
Rosie is sporting a new version of this rig, which is still under construction, but works much better than the older one, which Dartan is still using here. Rosie's was made after reading Digital Lighting and Rendering by Jeremy Birn, and I'm still doing stuff to it, but have had to take quite a bit of time away from Carrara lately. It includes a very subtle, well-aimed light that only enhanced the surface of her eyes. There are more little tricks that are going into this one, which is my next major step - finishing this rig.