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Say Joe, is the first image that shows in your post the final composite, or is it the last one?
I know that when Sub7th used to post here, he was a big fan of the layer passes, especially the shadow pass. He would render a shadow pass with hard shadows and use AE to blur the shadow pass and get the benefit of a soft shadow look without the time hit in the render room.
Now, why do you use, for example, a "multiply" blend mode for the shadows?
Well, multiply makes stuff darker. You basically multiply a pixel value on one image/layer by the corresponding pixel value on the other image/layer.
What does that mean? Well, it's a bit like having a tinted window. Lets say you're looking out of a stained glass window. Lots of beautiful colors, right? Now take a dark gray tinted glass and place it over the stained glass window. What do you get?
Well, you can still see the stained glass window and the colors right? But the gray glass makes everything darker.
The gray glass has been "multiplied" with the stained glass to make it darker.
That's what multiply does, it makes things darker. And that's why it's used for a shadow layer. It darkens the underlying diffuse color layer and makes it darker. You still see the colors, but they are darker.
Huh? The last one, the one without shadows, is the diffuse pass. The first one, with shadows and diffuse and specular, is the final rendered image. I thought that was obvious.
And yes, that's what you often do with a shadow pass. You blur it to get soft shadows, rather than have your renderer spend 3 weeks rendering the soft shadows. Like I mentioned before.
But you also need to make sure the shadows are on the correct layer, "under" the object, so the blurred shadows are correctly blocked by the object.
Huh? The last one, the one without shadows, is the diffuse pass. The first one, with shadows and diffuse and specular, is the final rendered image. I thought that was obvious.
And yes, that's what you often do with a shadow pass. You blur it to get soft shadows, rather than have your renderer spend 3 weeks rendering the soft shadows. Like I mentioned before.
But you also need to make sure the shadows are on the correct layer, "under" the object, so the blurred shadows are correctly blocked by the object.
Well, that's what I thought, but sometimes the forum software re-orders them. I just wanted to make sure I was looking at them in the right order.
I think what's frustrating is that we've entered the age of what I call "spoon feeding". People *expect* to sit back and have someone do all the work to provide detailed, step by step tutorials and pictures and videos and arrows pointing to show you exactly what to do.
My problem is that I grew up in an age where none of that was available (pre-internet), so the prevailing attitude was that you do the investigation yourself. And the side benefit is that you learn better, with a deeper understanding, and it tends to stick with you if you put in the effort. I just hope the skill and desire of taking concepts and figuring out how to implement them isn't becoming a lost art. I keep feeling that the internet age is nothing more than a "I'll sit back while you entertain me" age.
If someone tells you "push this button, then this one...", then yeah, it might do something you want, but you don't necessarily understand what you're doing and why. You just know "how". But the emphasis here has always been more on the "how", and operating software, as opposed to an in-depth understanding of "what" and "why".
Anyway, just the frustrated ramblings of a clueless old guy I suppose... :) :)
Hi Joe,
I'm usually a lurker, but I wanted to thank you for this thread. I've been wrestling with compositing since I started learning Carrara, but I've been frustrated by the few tutorials I've found and how to reinterpret them with Carrara.
I suspect I can be accused of wanting to be spoon fed, but I work 50-60 hours a week at my unrelated job, and I'm doing my darnest to learn as much as I can on my own time. Every bit of info I can find helps and is appreciated, Christine
Maybe I need to give some more clarification on the "object index" pass. It can be extremely useful, though the implementation in Carrara is sorely lacking.
In any case, as I've said before, one of the most important concepts in compositing and post production work is "isolation". Isolating the parts of your images so you can modify each aspect.
And often you'll want to separate out, and isolate, some or all of the rendered objects in your images so you can modify, add, or delete them. Again, a large part of what you do in Photoshop or After Effects or Nuke or Fusion or Gimp or any other image manipulation application revolves around selection and isolation.
So, using Evil's image as an example, let's say you want to apply a depth of field blur or fog or whatever to the background behind the main character. To do so you'll need to separate and isolate the background so when you apply a blur or fog it doesn't cover the character also. So you need to find some way to isolate the character.
In Photoshop for example, you can do that by selecting the character and putting that part of the image in a different layer. So one layer is the character, and another layer is only the background. Then you apply your blur or fog to the background layer, and it won't affect the character in the foreground layer.
So how do you select and isolate only the character? Well, there are many selection tools available. But one of the easiest ways is to plan ahead when you do your render in Carrara. It has what's called an "object index" render pass which gives you a separate channel in the final image that provides a grayscale image. And the image has different values of gray assigned to each object.
Below is a final image I made of over 260 replicated spheres, looking down from above. And below it is the "object index" channel image that Carrara provides.
Now, unfortunately, what Carrara does for the object index (normally referred to as "object ID" in other software) is apply a grayscale value from 0-255 for each object in the scene. Remember that 0 is black and 255 is white.
In this case, since there are more than 256 spheres in the rendered image, Carrara runs out of Object ID grayscale values. Also unfortunately, the grayscale values it applies to each succeeding object are only 1 RGB value apart (eg, one object is RGB = (1,1,1), then the next is RGB = (2,2,2), etc.), which means if you only have a few images in the scene you're seeing grayscale values of maybe RGB = 1, 2, and 3 applied to those images. And those grayscale values, as you can see in the top of the previous image, are barely visible.
What most rendering apps allow you to do is select whether it will apply colors to each object in the ID pass, what colors you want to apply, or what Object ID it will apply to each object, and whether multiple objects will have the same ID (useful if you want to group the objects together and do similar stuff to them), and many other options that make compositing much easier and FAR more flexible and efficient. Unfortunately, Carrara is sorely lacking in this and other departments.
In any case, you can take the grayscale image that appears in the Object Index channel of the rendered image, and using the selection tools, select the objects that you want to modify and place them on their own layers in your compositing app.
And some compositing apps even allow you to automatically apply a matte/mask to each object based on its Object ID, thereby allowing you to automatically select just that object to apply whatever effects you want.
In any case, I'd suggest you try rendering a simple scene with an object index pass in Carrara. Then bring that image into Photoshop (or better yet, a good compositing app) and select an object based on that ID grayscale. Once you have the object selected you can easily make a matte/mask to isolate that image so you work only on that object in your rendered image.
I'm kinda rusty on my PS, and since most good compositing apps automatically generate a matte based on the ID, I'll have to see if I can spend a little time doing it in PS. But I think it's just a matter of selecting the Object ID channel, using the selection tool with a very low tolerance (since each object is only 1 RGB value difference), and using that same selection for the main image.
Oh, and one reason I recommend that folks at least consider learn a bit about Blender is that it has a built-in compositing feature which is node based, and really quite good for a free app. And I recall it has a lot of neat render pass and Object ID matte features that can make things much easier.
Or you can download the excellent professional compositing app called "Fusion" which was recently released for free. It has just about any compositing feature you'll ever need. And when they release the other professional app called "Nuke" early this year you'll have a lot to choose from.
And here's a super simple change I made to just one of the spheres in an array of over 260 spheres. I selected all pixels with an RGB value of (176, 176, 176), and that effectively selected the 176th sphere in the array. I then cut that part of the image to a new layer, applied a Color Balance to it, and voila, object 176 is now yellow.
Now if your image contains a character with hair and clothing objects, you can select all of those objects by SHIFT-CLICK (or by grouping in some of the better compositing apps), and put all the character-related objects in a separate layer. Which, by the way, is exactly what I did with the first images in this thread, in order to separate Angelina from her background. Select all of the objects associated with her and put them in a new layer.
Or, just put the hair object in a layer and make whatever modifications you want to it. The possibilities are endless.
Now, someone mentioned Blend modes like those used in Photoshop to blend layers.
I'll give a quick rundown of what they are and what they do, but don't expect that there is a real good answer regarding what you can expect from each blend mode, cuz usually it's not really very predictable exactly what the result will be. But you can get a general idea.
First of all, I hope you're familiar with the "Levels" adjustments in Photoshop or other image apps. It basically allows you to adjust the "luminosity" (aka brightness) levels of your image. Basically luminosity is an indication of how dark or bright a pixel of the image is. Of course, black is totally dark and white is totally bright.
What the blend modes generally do is work with the luminosity levels of the layers they are blending. Like I mentioned with the "multiply" mode, it darkens the image. Like if you hold up a dark gray tinted glass to a colorful stained glass window. You see the colors of the stained glass window, but they are just darker. Other modes brighten the image. But the various modes brighten or darken various aspects of the image.
The blend modes listed in Photoshop are grouped according to what general effect they have. If you look below you'll see the modes menu along with a description of what general effect they have.
So for example, the Linear Dodge (Add) mode basically adds the luminance levels of the pixels in the two layers it's blending. Which means it will make parts of the image lighter.
Unfortunately, like I say, you usually won't be able to predict exactly what result you'll get, and you'll have to scroll thru the modes to see what effect they have. But after a while you'll start to realize what they are doing.
Joe and EP - brilliant, thank you :)
What Joe was saying earlier about "spoon feeding" prompted me to get all philosophical about teaching vs educating.
I. and I guess most other folk, learn best by having the subject put into context -the big picture - then the basic principles, then the detail. This is the way I did it when teaching Labor Law and Conflict Resolution at what you would call College level.
One of my pet hates as far as our education system is concerned is that teachers specialize and focus only on their subject, without providing the big picture. They don't educate, they teach kids to pass exams. They do this because their pay and promotion is based on their individual pass rates. Only when kids get to College level does it all get put into context. Problem is that the majority of the population don't end up going to college, so end up being able to repeat by rote, without understanding.
Here's a timely quote from another current thread; "Now there are about 5000 pages to go with much more “modeling.” If having context before detail helps you understand, then Vaughan’s approach in general, and this book in particular will probably be good for you. if you are the kind of person that just wants a description of tools that are commonly found in current 3D apps, then you might get frustrated with the first 20% of this book."
How does this tie in with this thread? Joe provided the big picture - the aim, goal, vision, mission statement, call it what you will (the "why"), EP provided the detail examples - the "how" (and when working in an unfamiliar software, this technical part is vital to understanding), now Joe has provided the missing part - the underlying principles.
Unless all three are present, the reader may be "taught", but not "educated", so is not in a position to undertake informed self-development without stumbling around in the dark. For this, I salute and thank you both:)
Just to show that I have pretty much caught on and can learn further without having been spoon-fed, I did a render in which one of the items used a shader under misc named "Young planet". This shader has red lava in it. I was puzzled as to why this red lava didn't show up in the diffuse layer, which is where I expected it, being a colour. Took a look at the make-up of the shader and saw it had a separate texture map in the glow channel, so did a glow pass. Sure enough, there it was to complete the picture!
So, to really get understanding across, as opposed to imitating, don't focus on only one of these aspects, they all three have a vital role to play :)
Now, if anyone is interested in a little deeper understanding of blending modes, it might be instructive to look at how the math in the blending modes relates to what the result is after blending.
Take as an example the blending of a shadow pass with a diffuse pass.
First, keep in mind that a diffuse pass is ONLY the colors of the render. That's it. Nothing else. No shadows, no reflections, no ambient occlusion, no effects....just color.
And as we saw in the images I posted, a shadow pass is a whole bunch of pure white, with some spots of gray or black where the shadows are. I've re-posted those images below.
So first of all we know we want to darken the diffuse/color pass using the gray/black information in the shadow pass image. We don't want the white parts of the shadow image to have any effect, just the dark shadow parts.
Now, keep in mind that the blending modes convert the luminance of each pixel to a value between 0 and 1, where 0 is black and 1 is white. And you want to use one of the "darkening" blend modes (darken, multiply, color burn, linear burn, and darker color).
And I mentioned we chose multiply for the shadows. Why is that? Well, we learned in math class that anytime you multiple a number by 1, you get the number. So, for example, 0.73 x 1 = 0.73. And that's exactly what happens with a multiply blend mode. The white part of the shadow image has a luminosity of 1, and the corresponding pixels in the diffuse image you are adding the shadows to has a value that is probably somewhere between 0 and 1.
So when you multiply the diffuse pixel with the corresponding white pixel of the shadow image, the result is the diffuse image pixel, unchanged. Cool, just what we want.
But when you multiply the dark/shadow area of the shadow image with the corresponding pixels of the diffuse image, you darken the diffuse image. You are effectively applying the shadow to the diffuse image using multiplication.
Bottom line, when you multiply the white areas of an image, the image is unchanged in that area. That's why you use multiply for shadow passes.
And a little trivia that might help to understand some of the blend modes and tools in an app like Photoshop....
Before there was digital photography, photographs were made by exposing a roll of light-sensitive film inside a camera. You then took that film, which had "negative" images of your intended photographs, into a darkroom. Which was basically a room that was sealed so that no light entered. And it was really really dark. :) :)
You then took a piece of pure white, light sensitive paper, which was to become the physical photograph. You place the white paper in a contraption which had a bright light source. You shined the bright light thru the "negative" film from the camera, and "exposed" the white, light-sensitive paper.
Now, the longer you exposed the white paper to the light, and the brighter the light, the darker the paper would become. So if your intended photograph was quite dark, or had some very dark areas, you'd need to expose the paper to the light for a longer time. But if the photograph was very light, then you'd only expose it for a short time, then turn off the light.
And there were some techniques for doing what was basically post production work on your photograph while you were exposing the paper like this. And it involved how much light you allowed to hit the white paper, and for how long.
So if, for example, you had an area of the image that you wanted to lighten, you could block the bright light in that area while you're exposing the image. It was called "dodging". You take a little paddle-looking device and actually block the light hitting that area of the photograph while you're doing the exposure.
The opposite of that was when you wanted to darken an area of the photograph. To do that, you take a big, square, plastic sheet that had a hole in it, and block all of the light EXCEPT for the area you wanted to make darker. That was called "burning".
So dodging was lightening, and burning was darkening. You were increasing or decreasing the luminosity of parts of your photograph. Same as the tools and blend modes in an image app like Photoshop.
And to get a little deeper, keep in mind that you were exposing your pure white photograph paper using a bright light and a "negative" image of what you photographed. So with a little thought you can see that bright areas of the real world that you photographed become dark areas in the "negative" film, and vice versa. So when you are exposing in the darkroom, the dark areas of the negative block the light, leaving the white areas of the photograph paper intact. So real world "bright" becomes dark in the negative film, but is converted to bright again because you are blocking the exposure light, leaving the white photo paper white....
Wow, I actually found a photo of a guy using a dodge tool... :) :) :)
I agree. No question, there are good teachers and not-so-good teachers. But I don't see that a discussion of teacher skills and abilities is really appropriate here.
IMO, what is far more appropriate is a discussion of respect, expectation, and initiative.
Keep in mind that nobody here is paid to post or share their knowledge. Nobody. It is voluntary. We all have real lives beyond this forum. Well, at least most of us do... :) :)
Someone recently posted how he's working 50-60 hours per week and doesn't have much time to learn stuff. Many of us are in similar situations. But even if we're not, our time is our time, and nobody deserves to take our time with their needs or requests.
Therefore, we should respect each others' time, and recognize that it takes our own time to provide information here. And we could be spending that time doing other things. Unfortunately, in the internet age people have come to expect everyone else to spend their time doing what we want them to do. That, IMO, is very disrespectful.
Personally, I think people should take the initiative for their own learning, instead of expecting others to spoon feed them. But that sort of initiative is pretty rare on the internet. People are so used to being able to sit at their computers and click buttons and download whatever entertainment they want, and not lift a finger to do their own work or learning. They expect companies to offer free software and free videos and free training. Training that is laid out, step by step, with big arrows to tell you what to do.
That's not learning. That's being entertained.
And while I'm at it...
This being the internet age, it is FAR less important, IMO, how our teachers perform. Why? Because you can find just about any information you want in a few clicks. There's Google. There are tons of learning resources from all over the world, just a click away. NONE of that was available decades ago. You relied on your teachers and whatever books you can find in the library.
Personally, I feel there aren't many excuses nowadays for not learning stuff. It's easy, all it takes is a TINY bit of initiative and a few mouse clicks.
Sure, it's not always laid out perfectly so we can understand it immediately, but guaranteed the basics of most subjects are there if you just do a tiny bit of work. And I'm talking about 10 minutes of Google searches, not hours of study. But even that is too much for a lot of folks nowadays.
Hard to understand.
I agree. No question, there are good teachers and not-so-good teachers. But I don't see that a discussion of teacher skills and abilities is really appropriate here.
IMO, what is far more appropriate is a discussion of respect, expectation, and initiative.
Keep in mind that nobody here is paid to post or share their knowledge. Nobody. It is voluntary. We all have real lives beyond this forum. Well, at least most of us do... :) :)
Someone recently posted how he's working 50-60 hours per week and doesn't have much time to learn stuff. Many of us are in similar situations. But even if we're not, our time is our time, and nobody deserves to take our time with their needs or requests.
Therefore, we should respect each others' time, and recognize that it takes our own time to provide information here. And we could be spending that time doing other things. Unfortunately, in the internet age people have come to expect everyone else to spend their time doing what we want them to do. That, IMO, is very disrespectful.
Personally, I think people should take the initiative for their own learning, instead of expecting others to spoon feed them. But that sort of initiative is pretty rare on the internet. People are so used to being able to sit at their computers and click buttons and download whatever entertainment they want, and not lift a finger to do their own work or learning. They expect companies to offer free software and free videos and free training. Training that is laid out, step by step, with big arrows to tell you what to do.
That's not learning. That's being entertained.
I understand what you're saying about respect Joe, but I would point out that it works both ways, which, quite honestly is why your first thread about this subject tanked. Specifically a lack of respect directed at the people that frequent this forum.
And as to being spoon-fed information, if you don't feel you have the time to get into the nitty gritty mechanics of how to actually do the things that you are talking about, that is very understandable. However, I fail to understand why you were so frustrated when I posted my response to Roy. I never said you were wrong or didn't know what you were doing. Quite the contrary actually. In fact everybody has gone out of their way to thank you for this topic. But what do you do? Someone that went out of their way to thank you for this thread and the overview and information that you provided and also thanked me for the steps I took, and explained why she was thankful, due to long work hours, instead she gets a backhanded, snide little aside implying she was to lazy to learn it for herself or just wanted to be entertained.
Up to this point, you have been shown nothing but respect in this thread. Don't you think it is about time you showed it to others? And no, I'm not talking about myself. There may be a little too much water under the burned bridges for that. ;-)
Take it for what it's worth. I've said my piece about it. I won't derail the topic anymore.
Evil, I realize you're constantly assuming bad intentions and motives, and that I'm directly attacks at others, but it just ain't true. But I'll never change that belief, so I won't try.
Suffice it to say that respect is earned. You may like someone, but not respect their actions or attitudes for whatever reason. My only disrespect to anyone here is when people clearly seem disinterested in putting in a minor effort to learn the basics. That's it. No anger or animosity or attacking or hatred, just a lack of respect for an apparent attitude of disinterest in learning and improving. But that's just me.
I respect those who want to learn and improve. That's just how I am. Others may not care. People are different. Nothing to do with like or dislike. But if you insist on equating a lack of respect in one particular area with personal animosity and attacks and anger, that's up to you.
Personally, I have a lot of friends, but I also don't respect every attitude that each of them has. Nor, I'm sure, do they all respect every attitude or action I take. Nobody is perfect. Doesn't mean they aren't my friends, we just don't agree on our attitudes on everything in life.
Now, for the next step in our challenge to try to reconstruct a final render by blending the appropriate render passes, we'll add some reflection.
I only added a 50% reflection to the sphere in the scene, no other changes. And the result is a color image on a pure black background which contains ONLY the part of the render which contains the reflections.
Now, before we try to blend it, let's see if we can figure out what blending mode to use.
First, we know that reflections will add color and luminosity to the image in the areas where the surface is reflective. And outside of that, there should be no affect to the underlying image. So that sounds like a "lighten" type of blending, right? And if you look at the math that I mentioned, if you add black (luminosity of 0) to an underlying image, there will be no change in the underlying image. However, where you add the reflection it will add to the luminosity and color of the underlying image.
So that sounds a lot like we'll need to use something like a "Linear Dodge (Add)" blending mode, same as we did with the specular.
Below is the reflections layer, and the final image with the reflections added to the rest of the layers, and a list of the selected layers. As you can see, the complete, final render can be reconstructed by blending only the Reflection, Shadow, Specular, and Diffuse render passes.
And next we'll go into the render tab and turn on Indirect Light, and add a render pass for Global Illumination.
Let's try to guess what we'll need for a blending mode....
What is the general effect of Global illumination? Well, it simulates light bouncing around and lighting areas that otherwise aren't lit. Which tells us we'll probably need some sort of Lighten mode.
So we do a render, and it gives us a Global Illumination layer in our render image. And we notice that, same as with Reflections, it is a black image with ligher areas where the bouncing light is increasing the luminosity of the scene objects. So we guess (and we'd be correct) that we need to use a Linear Dodge (Add) mode again for GI.
Attached is the GI render pass image, and the final rendered image composed of only the render passes blended together.
Now we have figured out how to take five Carrara render passes and put them in separate layers so we can manipulate them as much as we want, then re-combine them back into the final image.
Of course, Carrara has many other render passes we can use. There is a "Post Effect" pass which holds only those (you guessed it...) post effects that are applied after the render, such as Light Effects (cross screen, glow, nebula, etc.) and lens flares and stuff.
Here is a final render where I added a low level bulb light in the scene, with both a Cross Screen and Anamorphic lens flare post effect. Note that you get a separate layer for each post effect so you can tweak them individually.
Also, note that the post effects are automatically given a Screen blending mode.
Anyone know why ?? :) :) :)
Carrara also has an "Atmosphere" render pass, and that gives you the atmospheric/Realistic sky information in separate layers. It gives you two layers, one Add and one Multiply, presumably to isolate the sky and ground effects in separate layers. And if you want to include the clouds in another layer, you can select the "Volume Primitive" render pass, and it will also give you two separate Volumetric Layers (Add and Multiply).
Here's the result of adding a Realistic Sky atmosphere in the scene, and including an Atmosphere and Volume Primitive render pass. The final image, plus the combined atmosphere/volumetric layers, and the layers list.
Okay, I'm running out of energy to continue with the available render passes. I'd suggest if you're interested you just select a bunch of passes, bring the image into PS or whatever, and start clicking visibility on each layer to see what it looks like, see how it adds to the overall image. Then, see what cool ideas you can get from considering each pass separately, and how you might modify or even delete them to get a new, cool image.
I'm especially interested in the Material Diffuse and Material Specular passes and how they are implemented in Carrara. I'll save that for another time.
EDIT: Oh, and by the way, I didn't spend much time on it, but it appears that the Atmosphere render pass only provides the contribution of the Realistic Sky to the colors and features of the sky itself, but there isn't a separate layer which contains the overall scene lighting contributed by that feature. In other words, the Realistic Sky simulates the direct sunlight as well as the blue sky light bouncing around the scene and lighting up the objects, but there doesn't seem to be a pass which isolates that sky light illumination so you can tweak it. Maybe (and I hope) I'm wrong...it would be great if someone could do a little research to see if it's in one of the other passes. But at least it contains the layers where you can go in and modify or make invisible those sometimes annoying sky/cloud images, when often all you want is the sky lighting contribution in your image. Just click on visibility and voila, it's gone.
One thing I should also mention is the use of shadow passes from Carrara, for things like blurring shadows in post, etc.
For simple things, yeah, you can probably do some of that. But keep in mind that when it comes to shadow passes, especially in something like Carrara, it becomes very difficult to do much work with shadow passes. Below is a final render, plus the shadow pass that comes with it.
As you can see after examining the two images, just blurring shadows in this simple image can be quite challenging. First of all, you'll notice an overall tan/light brown tint to the object areas of the shadow pass. I *think* that's generated from the Realistic Sky, since it doesn't seem to exist with that is turned off. I'm guessing it's a darkening and tinting of the objects due to the slight shadows cast by the volumetric clouds.
And also notice that when you have a reflective object like the sphere, it can reflect its own shadow (see the final render image). Now, how are you going to blur the cast shadow as well as its reflection in the object's surface? It can get real complicated.
And then look at the last image of a shadow pass from a render with many objects. There are lots of complicated shadows that you'll probably have to separate and operate on independently, while making sure they remain behind the objects which cast them.
My only point is that, while post work on shadows is common, many professional apps have the necessary tools, while Carrara is extremely bare bones, and might require a lot more work than it's worth. Maybe it's just better for you to do your shadows directly in your render.
Food for thought....
AOVs and post processing (tone mapping, glare and LUT in primis): these are 2 topics we should consider too, that each engine should have as ultimate tools
http://renderman.pixar.com/view/using-aovs
http://rendermansite.pixar.com/view/TGT_Compositing
And now, back to the grind....
I took the shadow pass I posted previously and selected only the primary cast shadow from the sphere using the PS "Color Range" selection. That shadow was clearly far too sharp, and I also wanted to get rid of that annoying secondary shadow that arrived when I added the low level bulb light for my star/lens flare object. And I wanted to remove the overall tan color from the Realistic Sky, since, when multiplied, it dulls and darkens the floor a bit too much.
I then deleted everything else, did a quick blur, and replaced the original shadow pass layer with the modified layer. I decided to use a Linear Burn blend. Why? Just cuz it gave me what I want. :) :) :)
Attached is the final image, along with the modified shadow pass. By the way, as I mentioned, I was kind of limited on how I blurred the shadow, since there was a reflection of the original shadow in the sphere. And I didn't feel like going in and messing with that too.
Also, it goes without saying, since I just said it, but obviously you don't need to think that the only thing you can do to shadow passes is blur them. You can get rid of unwanted shadows, change their color, brighten or darken them....the list is endless.
As you can see in this image, the Linear Burn blended with the rest of the image in such a way as to enhance the apparent bumpiness of the stone texture on the floor. It's those kinds of subtleties that you won't realize until you try it. Just scroll thru the blending modes and see what you get. Often you'll be very surprised.
And I guess it also goes without saying, but if you look at the modified shadow pass I did, it's really pretty simple. In fact, it's simple enough that you might even be able to paint something like that from scratch, on your own. Make your own shadow. Using the actual shadow layer as a guide, and maybe give it a low opacity so you can see thru it, just use the PS paint brush, make it hard or soft as you'd like, and just paint whatever shadow you want.
That's one of the many, many untapped and unexplored and rarely even considered areas of 3D image making for most hobbyists I think. Just my opinion....
Often you can get great results just by painting stuff from scratch. Shadows, flames, smoke, haze, compositing layers....again, the list is endless. I think long ago I showed how you can quickly generate something like smoke and flames in PS just by drawing it yourself. Just use a reference image and try to reproduce it.
It's not cheating. Really. I promise. It's totally legit. And with a little effort you can have some wonderful results. Especially compared to the, well, less than wonderful results you'll get from some of the equivalent Carrara features. Honestly, if you can't draw flames by hand that are 10 times better than what you get from Carrara, then ask a 6 year old. :) :) :)
Hopefully the 6 year-old has a graphics tablet - wonder how he'd cope with an animated fire ?
Just kidding, Joe :)
Yeah, but if you look at an image of real fire, it's not all that difficult to reproduce. For a simple flame you've pretty much got only one color. You just need lots of layers at varying opacities to simulate the varying transparency of the flames. But compared to the orange splotches you get from Carrara, anything is better IMO.
And as far as animating it, yeah, that's some work. But keep in mind that there are many tools you can use on a flame image to simulate motion over time. Just select the layer with the matte'd flame and you can squash, stretch, move, bend, whatever and keyframe that over time. Or blend with a second layer of a slightly different looking flame, and vary layer opacities.
Personally, I think that compositing an image or video of real fire, or a good simulation of real fire, is the way to go. Or spend a few minutes to generate some nice smoke and flame in Blender. But I suppose for the Carrara purists that's a no-no, and apparently even the mention of that is boring or whatever. So I won't mention it :) :)
But what you get for flames in Carrara is, IMO, pretty useless, and a perfect opportunity to employ some compositing skills.
And by the way, speaking of fire...
At the beginning of this thread I mentioned that compositing can be used to bring various elements, generated in different apps or sources, together into one believeable result.
This is a super simple example of a composite that was integrated from multiple sources, to make up for, IMO, a deficiency in Carrara’s ability to render a believable fire/smoke simulation.
http://youtu.be/1pJ-8a5v1iU
The flames were rendered in a professional app called “FumeFX”. The colored flame/smoke was generated by the particle system in a compositing app called “Fusion”. And the background was a simple render done in Carrara (or maybe Blender, I forget). The separate elements were generated separately, then brought together in Fusion for compositing. The flames had to be scaled and moved, and a Glow was added. Same with the smoke simulator. And the speed of both the flame and smoke simulators was modified so that they match, and look more believable.
Below are frames from the individual component animations that were used in this. If you study them a bit, you'll notice that you cant just add all of the elements together in different layers of your compositing app and press render and get a result. You need to do stuff like:
1. Match colors,
2. Resize,
3. Move the elements into their correct location with respect to each other and the background
4. Add whatever effects you want.
5. Modify opacity of the elements so they integrate seemlessly
6. Match the speeds of the animations so that the flames generated in FumeFX, for example, move at the same speed as the smoke layer generated in Fusion.
And that's just the beginning. The animation you see still needs to, for example, be integrated with the background. A fire like that would throw light onto the floor and wall. There would be shadows as the sunlight passes thru the smoke and flames. And so on...
Now, in a good compositing app, doing each of these is very quick and simple. You just need to know WHAT to do to properly integrate the elements together.