3D
Intro screen for Adi
A quick short test intro screen for a local animation company. Done in 3Ds Max and After Effects. Particles and modeling/lighting done in Max and the main blue swoosh is done in AE. 4 hours or so of work.
Adi_test_intro from Jonathan Beals on Vimeo.
Maya Ascii
I posted about this topic earlier, but I felt a real world example would be beneficial to everyone. In an earlier post, I had said that if you saved an .ma and your project crashed or you couldn’t open it for some reason, you could go through that file in a text editor and find the problem. I just lived through this hellish problem. I had been working on my shoe and saving and iterating as normal and then I tried to merge vertex and it fatal errored. When I tried opening the last file I had saved, I found out that it had been corrupted and could not open. Since it was an .mb I was out of luck and my last iteration saved was 2 hours prior, which really isn’t too bad. Fortunately Maya successfully saved an .ma in temp when it crashed.
This .ma was almost 400 megs and it was too big to open for notepad, but astonishingly wordpad was able to open it (doh!). This file was over 500,000 lines long, so long that wordpad had to open it in sections and ended up taking about 20 minutes to fully open. Generally an .ma is structured in this way:
Basic File Info (name, date etc…)
Camera nodes and tranformations
Other node information (creation, transformation)
Lights
Layers
Histories of objects
Animation Histories
ConnectAttrb of lights/shaders/materials
Now granted this information could be off and should taken with a grain of salt, but GENERALLY this is the order.
Since I knew what killed it (MergeVertex), and where it was located, I scrolled down near to the bottom and searched for “MergeVertex”. I found it and deleted it then saved but it still didn’t open. So I figured it had to be linked to its history so I deleted the entire history of the object and all of its connections (basically the entire last bit of the .ma). Be very careful when you do this and make sure the structure stays in tact and semi colons and such remain in the right places.
After this I was then able to open it up. Everything was in Chaos-all my display layers were deleted, things were misnamed-utter chaos and of course no materials existed on the objects. But this was fine, since I had prior working scenes and I just needed to export and import the object that I had been in the middle of working on when Maya died.
So in Conclusion, make sure you save an .ma at least once per work session and if you do need to root through one, especially if it was as big and scary as mine, do it smartly. Know what you are looking for and where it is located. If you are not sure what caused it, it usually is one of the last things you tried to do.
Also, a lot of times fatal errors can be caused by conflicting preferences so move your preferences and try and opening the file first and see if it does it, if not move your preferences back and start rooting away!
Light Setup
I have finally gotten the time to create a new lighting scene for Adidas. Finally, I can get them working linearly! Quite simple, and still in its early stages. My test subject is a scene off of http://www.mymentalray.com/. I am using 3 portal lights, along with 3 softboxes in front of them to soften the shadows. I am using 2 blackbody shaders in the lights and 1 cie_D (blackbodies have a more saturated color, while the cie_d is less saturated). Of course the lights are visible. I am also using final gather and AO within the MIA for the cloth. Kelvin temps of the lights are 5K, 6.5K, and 5.5K and the kelvin control in the lens shader is set to 5.5K. All MIA_X mats. There will be multiple variations of this scene, including a layer that has harsher lights and shadows, different background attributes and etc.. You can see where I put my lights by looking in the chrome ball ;)
Oh and if you notice, you can see in the center of the area light is a bright point. You can see this strongly because the softbox that is in front of it, intensifies this flaw. This proves that area lights in Maya emit more from its center and not uniformly. Can’t wait for 2011 to test this out with the new physically accurate light.
Adidas Enduro Bounce WIP
I have begun the laborious task of replicating an Adidas shoe for the glorious reel. It is called the Enduro Bounce II. This will be high poly and will completely and accurately match the real life shoe. I want to keep things quads and as close to the same relative size as possible so if I need to take things into Zbrush, it will behave nicely. I will be modeling every part of this shoe and of course texturing/lighting/rendering later on. I have started with the sock liner since it was the easiest to get the proportions correct on. Here is the sock liner (the cushy part you put your foot on in the shoe) half completed.I have the shoe in hand and of course have lots of reference images and the such to go by. I’m makin sure the edge loops flow right and every edge loop has a home :-)
here is the actual shoe more or less (found the pic on the web because I’m too lazy to upload one of my own):
Ambient Occlusion
Throughout the years I have always been told to render an AO pas and multiply it over the beauty and fuss with it to make it “correct.” This method has always looked incorrect to me and always makes things look dirty. But I was always the student (and will always be in a sense) so I never thought to challenge it, and thought I was wrong. Well ladies and gentlemen, I am about to link you to a post on Master Zap’s blog that will rock your world and will change how you do an AO pass (hopefully).
Here is the image:
and here is the article
http://mentalraytips.blogspot.com/2008/11/joy-of-little-ambience.html
Illuminance Continued
*Generalizing Alert*
my notes continued.
So say you have a point on a surface and you want to find out how much illuminance it is getting. What we do, is look at the light source and see how big of an angle it covers. We take that angle, multiply it by the amount of luminance the light has and you get the illuminance value at that point. If the light source is bigger, it covers a larger angle. If the same light is farther away, it covers a smaller angle which means the illuminance of that point is lower. Distance is irrelevant actually. All that matters is the size of that angle. A large light from a far distance and a small light at a near distance that covers the same angle and same luminance value will give the same illuminance.
You have heard the term “light falls of quadratically” or at least seen the option for the light in Maya (distance^2). This is actually a fairly inaccurate representation of the above subject. It is only accurate for distant lights. Example. You have a plane of light that has a length of X meters at a distance of Y from object P covering an angle of Z. If you were to half the distance between the light source and the object, the angle of course gets bigger, and at far distances it’s really close to doubling the size of that angle Z. However, since the light source can never reach point P, that means the angle can never grow past 180 degrees. This means that for each time you half the distance, the degree that the angle changes will grow farther away from doubling and closer to staying the same.
Example. Walk up to a large light source such as a window or tv. Look at your hand as well as how bright the tv/window is and notice how bright it is. It has a specific luminance. Take two steps back and look at your hand, your hand will appear darker, but tv/window look to have exactly the same luminance. This is because when you were closer, the light source covered a larger angle compared to your hand and when you stood back, it covered a smaller angle which means it will illuminate your hand less.
There are many ways to imitate this in CG. For MR, you have your final gather, photometric lights, and of course the beautiful and amazing Portal Light.
There is a big problem with traditional cg lights because they are point lights. Points cannot cover an angle to a point on a surface because it has no area which means it cannot emit any illuminance. This means the objects in a scene does not know what luminance the light has so it is faked. It also has an unclear mythical 0-1 value of color which is of course unrealistic (value of light is from 0-whatever). Lights also have strange falloffs (none, linear, or tries to do a distance^2 blindly). They are also rarely ever visible in a scene like they are in real life. When they are visible, their intensity is computed incorrectly. Even old MR. lights are buggy and hacks.
The reflections of the light source is generated by a fuzzy blob. This is a big problem because our eye uses highlights to judge an object and figure out most of it’s features. If we make it visible so it can be seen in reflections we run into major sampling issues.
Let’s get technical with light and pixels
This post is going to be quite dry and lacking of pictures, I hope you will forgive me because this stuff is actually quite interesting. I have learned all of this through mindless perusing of sites, and blogs. Below is basically a summation of some of the teachings of Master Zap. And of course everything is generalized
When you talk about lights and units, you can break them (generally) into two categories. Radiometry and Photometry. Radiometry is what you measure. It is actual radiation and its base unit is the Watt. Photometry is what you see, it is the perceived brightness, and its base unit is the lumen. The relationship of these two is based on the relationship on the sensitivity of the human eyes. This is called the “Photopic Response Curve” For any spectra of light, it can be expressed as a number called “luminous efficacy” (lm/W)
As you can see from the graph, we see green the most–>exactly 555 nm of wavelength. So it will have a very high luminous value. Whereas over in the far left area of the violet where there is exactly the same amount of watts we will have a 0 photometric value to us.
Computer graphics is technically radiometric units, photometric units can be more useful.
. photometric radiometric
Luminous power = lm (W)
Luminous Intensity = lm/sr = cd (W/sr) cd=candela
Luminance = lm/sr/m^2 =cd/m^2 (W/sr/m^2)
Illuminance = lm/m^2 (W/m^2)
sr = steradian
radian=2d angle where the arc length of a circle is equal to the radius
circle =2pi radians
steradian
3d angle where the area on a sphere is equal to the square of the radius
A sphere covers 4pi steradians
luminous power = the amount of light leaving the entire light in every direction at once.
luminous intensity = the amount of light leaving the entire light in a particular direction.
luminance = the amount of light leaving a particular point on a light and goes in a particular point. Our everyday perception of brightness is luminance.
illuminance = the amount of light arriving at a particular point on a surface, but coming from every direction. A sum of all the luminances in all directions seen from a point.
Now you can begin to see how this is all related to the CG world and rendering. But what about pixels?
PIXELS:
A camera is a luminance measuring device.
Pixels can be many different things. They can be the actual brightness of something. R,G,B are proportional to spectral radiances. Weighted value is proportional to luminance. The range of this is 0 – whatever. You can have as much as you want. We cram these into low dynamic ranges and call it black to white. That is just the limit of the file type, not of reality. It can be how much something reflects (0-1 range) such as texture images.
Most computer graphics displays have a display of 8 bits of red, green, and blue. 0 is black, 255 is white and 127 LOOKS like middle gray, but even though 127 is half of 255, it is not half the brightness. The human eye is a funny thing. We perceive light in a non-linear way.
This is a perceptually linear ramp:
This is a linear ramp:
If you measure the values of luminance, you will see that the perceptually linear ramp is not right. If you really made the same change for each step, you would see a curve like the bottom image. We perceive huge jumps in the dark area and small jumps in the light area.
If we try and encode an image using the linear values it will look horrible, whereas if we encoded it using the perceptually linear values, it will look correct. This is exactly what the computer monitor does. The pixel response of the monitor is not linear. 127 is not half as bright as 254. This, of course, is called gamma. A computer’s gamma is typically 2.2.
All this means that your 8 bit images have gamma encoded into them so they will display correctly on your monitor.
When you work in an 8 bit format your gradients between colors become muddled and ugly.
All this creates disastrous results when rendering. This is why, when working realistically, you need to work in a linear method. There are tons of “how to’s” out there, I have even provided links in a previous post on this blog.
If you work nonlinearly lots of bad things happen. You get unrealistic fall offs, you get blown out effects when using physical lights, you also get artifacts around highlights. There is a weak propagation of Indirect Light, and you get unrealistically strong reflections. There is also a huge problem with motion blur, it looks dark and smudgy and highlights will not streak properly.
Swatches?
For you Maya USERS in the house!
Ever create a material preset that looked awesome and you want to save it, but you want that cool little thumbnail so you can find what it looks like again? Well I found out how :-)
I learned a neat little trick today that is quick enough I could share with all of you. Here is a quick tutorial on how to create those thumbnail images associated with your materials that you create.
Step One: Open the scene where you want your material to be rendered on the object you want rendered that has some good lighting.
Step Two: Open your hypershade and navigate to the library where your newly created shaders are. (I strongly suggest having one because things like to break when you start moving your shaders to new homes).
(Create new tab, navigate to the directory). MM drag the .ma material file into your scene and apply it to your object.
Step Three: Render (I suggest a 400X400 image, but it doesn’t really matter)
Step Four: In the render window where your new image is now sitting, click on view>grab swatch to hypsershade/visor.
Step Five. You will now be asked to draw a marquee selection around the area that you want to have as a thumnail.
Step Six: Once this is selected make sure you have your hypershade open and you can see your .ma material file in your library(The one that is sitting in your library not the one that is in your scene) . Middle mouse your selection onto this icon. It will replace that default icon with your new beautiful render of your material!
That’s it!
Fire Test
I’ve never really dealt with particles, but I have to say once you get on the right road, it’s pretty fun. The black outlines at the base of the flames are an outline of the logo that will go in it. I am getting some weird build up right above the letter though. hrmm…
My Procedure for matching the lighting and materials of a photograph
I was asked what my approach is to matching the lighting and materials in a photograph. If you have had to deal with this, you know it is fairly tricky. However, I believe if you follow these steps it will make things much easier and much quicker to do correctly.
1A.) In this write-up I am going to assume you don’t have any specific data from the shoot. e.g: light data, camera data, hdr probe etc…
1B.) Research. This can happen after the modeling bit or before-it doesn’t matter too much. Recently, I have had to match a photograph of a wine bottle. For my wine setup, I had to no idea how photographers setup their lights to light glass. It’s such a tricky thing to light. In fact you don’t even light glass-crazy right? You create reflections. I did not know this when I started and learned about it through my research. If you do a bit of research before, it will shave off hours of experimenting. You will learn little tricks and hints and see how they setup up their lights. That way when you see a reflection or highlight you understand how and about where that is coming from. Another good bit of knowledge is “family of angles.” This topic tells you based on the object from the camera, where a reflection will show up. Google is your friend with this area. Also know what you are ligthing. For example, you light glass and metal in completely different ways. Metal depends on reflections toward the camera, and glass depends on reflections on the sides. :)
1C.) Modeling. No matter the subject that you are trying to emulate, you have to try and model it as close to the photograph as possible, especially if it is highly reflective or refractive. Why? Well say you have the model pretty close to the photograph, but not exactly. The reason this will throw you off is because every surface point on your model that is different than from the photograph you will get a different light play than what is on the photograph, even if your lights are in the exact place in your scene as they are in the photograph. So you will not get the same highlights/reflections/refractions that the photograph is getting which will lead you to have to do hacks to make it “look” about the same. Which, in the end, will only cost you time and energy.
2.) Initial setup. As well with modeling, this part is key. First create a camera, never ever, ever, ever use the perspective camera to do these renderings. My favorite, and probably the easiest and quickest, method is to load the image as a background image and move the camera so your object is in the same place as the object in the photograph. Don’t forget to mess with the camera’s focal length to match the camera that was used. A more exact way is to measure out the vanishing points of the photograph, find those angles and recreate them in your 3D app. Key your camera or add a bookmark so you don’t lose your place.
3.)The real step one. Once you get your camera setup, setup your initial materials and a couple of lights just you can work w/ your mats. The mats don’t need to be exact. For this all I am saying to do is if your object is highly reflective, create a highly reflective material, if it has blurred reflections create something w/ blurred reflections, if it is glass create a quick glass with the appropriate colors of course. This way we can dial in where the lights are based on reflections and highlights.
Because we are trying to match real world materials, use physically correct materials, I believe every renderer has something like this in it now. DO NOT use a blinn or a phong unless you absolutely have to. If you do, make sure you get your falloffs correct. For mental ray stick with the Mia_Material (Arch&Design for you Max users). It even has nifty presets for metal and glass which is perfect for this step.
4.)Camera. Since we are dealing with the real world that means that everything has to be “physically correct” this includes the camera. This one I always go back and forth messing with. Sometimes I setup my lights first and then do this and other times I setup the camera first. I think it just depends on what you are doing and your taste. In this case I applied a photographic lens shader with just a basic light setup first.
5.) Lighting. I have found that messing with highlights and reflections first and doing the fill last is the best way to work. The highlights and reflections are the most obvious and so the easiest to nail first and then the fill will fall into place.
Make note of where the light sources are in the photograph. Generally real world photography deals with a minimum of 3 lights, sometimes 2. This is the point where you need to decide if you are going to try and match the lighting exactly as they did or if you are going to do some tricks that will give the same look, with less render time. An example of this is often in lighting, the photographer will shine a light at a bounce card which will bounce the light back at the object which creates really diffuse lighting and often a nice highlight. If you do this in 3D your render times are gonna skyrocket really quickly. An easier way is to use an area light w/ soft shadows and have it visible with maybe a reflect card BEHIND it. Gives about the same result w/ 1/4 the rendering time.
Also, I notice a lot of people have all their render settings turned up to max when testing. Don’t do this, it is unneeded. Turn down your aliasing to -2 and 0 instead of 0 and 2 and turn down the amount of reflections and refractions you have. If you are doing glass make sure they are high enough so you won’t get black in your refractions/reflections. These settings will lower your render time by half at least. Also if you are using fg or gi, lower these settings even if you get a little bit of blotchiness. Stop making life harder for yourself!
IF ipr will work for you in this part I would highly suggest using it. Create the light shape you need. If you are just getting a reflection then you can leave the intensity at 1 w/ no falloff, and ipr your scene and now move that light and manip it so you can get that same shape and size on your object. Once you get this in place hide the light and do the same for every reflection. Once this is done then unhide them all and go to the next step.
6.) Lighting Cont. Along with your mats and your camera, your lights need to be physically accurate as well. You have a couple choices in this area. You can apply a physical light to the light/photon emitter of a POINT LIGHT and then an .ies profile to that to emulate a specific light. WARNING: Maya has issues with this. Max is muuch much better if you want to go down this road. These profiles only seem to play nicely with point lights.
Another option, and my favorite, is to load a blackbody or a cie_d into the color attribute of your light. This way you can control the kelvin temperature and intensity realistically. Don’t forget to have a quadratic falloff and shadows enabled.
NOTE: The white point of your camera will affect the look of the color of your temp on your light.
Once you get the reflection properties down, hide these lights, and work on the highlights. You only want to work with one light at a time to make sure you know what is doing what. Once you get these dialed in, then unhide the lights and see how they work with each other and adjust accordingly. Once you get the highlights and reflections down then go ahead and apply the fill. You can hide the other lights and dial this in or you can do so with the other lights in the scene, since you are just adjusting the fill and if fg in on the fill will need the other lights.
7.) Finally finesse the materials, add textures, crank the samples. During this mode, cranking the anti-aliasing and refl/refr properties will be a good idea.