Realistic Earth-like planets in Carrara!
Need a high resolution Earth model as a backdrop for your blockbuster disaster movie? How about a newly discovered “terranova” for your space opera? According to news just this week, one in five sunlike stars observed by NASA’s planet-hunting Kepler spacecraft has an Earth-size planet in the so-called habitable zone, where liquid water — and, potentially life — could exist….
Kepler can’t *see* those planets directly. It actually recorded dips in the brightness of their suns, indicating a planetary transit. Since no one has actually seen them, it’s anyone’s guess how they will look…. I predict a bull run on Terra artwork, and we’re going to need a lot more planets!
To celebrate I’ve put together 10 Tips to launch your planet scenes into orbit!
#1 – HIGH RESOLUTION EARTH MAPS
Carrara comes with a complete Solar System of planets organized under the Scenes Tab in the Browser. An Earth model is included with a separate cloud layer. It’s part of the Native Content download that is free with purchase. These planets are great except for one thing, they use low-res maps only 1000 x 500 pixels.
Serious players will spend $8 to download the fullsize 10k Earth maps from JHT’s Planetary Pixel Emporium, which are prepped to be used in 3D models with color, bump, and a specularity map for the ocean. While you are there, grab the free 4k maps of the Moon!
Perfectionists will find the high res maps from NASA’s Blue Marble Collection to be the definitive reference, courtesy the US Geological Service at Visible Earth. Using a collection of satellite-based observations, scientists and visualizers stitched together months of observations of the land surface, oceans, sea ice, and clouds into a seamless, true-color mosaic of every square kilometer of our planet.
This remarkable collection includes different color maps for each month of the year so you can show annual vegetation and ice cycles, an extremely high res cloud map, and this stunning night-side map of city lights. These images are freely available to educators, scientists, museums, and the public.
What if I told you there is a single effect that can deliver more visual impact from your renders, allowing you to redefine reflection, highlight, and shadow with the contours of your scene objects. Create photoreal fabric and glass shaders, and enhance skin with subtle, flattering effects that render in a fraction of the time of subsurface scattering. Well it’s all true. It’s called Falloff, and it’s not included with Carrara but probably should be.
What is Falloff
Falloff is a value based on the viewing angle of the geometry to another point in 3D space, usually the camera. Polygons that face the camera receive a high value, while polygons that angle their surface away from the camera are given a lower value. You will often see the term fresnel (pronounced fra-nell). Generally, fresnel is used when discussing transparency and refraction while falloff refers to color or glow, but for our discussion the two words are more or less interchangeable.
As of Carrara8.5 there is no falloff shader included with Carrara. Fortunately we have several choices with plugins. Digital Carver’s Guild offers a simple Fake Fresnel shader with SHADER OPS. SHOESTRING SHADERS adds the more sophisticated Fresnel and Angle shaders. Sparrowhawke3D recently updated the Laboratory plugins for Carrara8.5, including a free Edge Falloff Shader.
Fake Fresnel in Shader Ops will always “point at” the rendering camera, but the Shoestring Shaders are more versatile allowing any scene object to be the “point at” object. All the examples in this article use the simpler Fake Fresnel shader. Links to the plugins are at the end of the article.
- EDGE POP
- METAL and ENAMEL REFLECTION
- GLASS EDGES
Let’s start with a simple falloff in the glow channel. See how the cherries “pop” from the dark background? They almost seem to float in space in front of the screen. This is because the extra contrast separates the layer from the background. If we were seeing this in real life, there would need to be empty space behind the cherries to create this kind of “light wrap” effect. Our eyes perceive the fall off as depth, as well as adding a kind of glossy highlight all around the curved surfaces. Use this trick anytime you want to make an object jump out and grab attention.
Instead of “popping out” of the screen, falloff in the Reflection Channel can help embed an object into your environment, especially when using an hdr background to wrap your scene. Hard surfaces made of metal or glossy enamel coatings start to reflect at oblique angles, even if they don’t have a highly mirrored surface. Airplane wings, automobile hoods, chrome bumpers, stainless steel tools, and ceramic-tile countertops are objects that will show more reflection when viewed edge-on. Adding falloff in the Reflection Channel also creates a better light wrap on hard surfaces when using hdr backgrounds and image-based lighting.
HDR courtesy http://www.hdrlabs.com/sibl/archive.html
Glass can be one of the most challenging surfaces to render in 3D. Even with extra lights and heavy refraction the edges of glass objects can easily disappear. A thin, bright, edge falloff glow gives glass more “presence”. As above, falloff in the reflection channel can also be added for additional photorealism.
An image-based light dome with dozens of individual lights can render much faster than HDRI Global Illumination. This basic tutorial shows how to create a low-poly dome in the Vertix Modeler as a reference. The process of setting up all the lights is automated by Carrara in one easy function called ENVIRONMENT LIGHTING.
Because I cut the dome from a sphere, the UV map of the dome is the top half of a sphere. In otherwords, you could use any seamless texture for the dome, even procedural patterns, but if you want a realistic texture you need to use something from a spherical camera, not just a panorama like I showed in the tutorial.
You probably don’t want to use a full sphere, because that will double the number of lights, and light your scene from under the ground plane….
Notice that you can see individual highlights from each EL light in the scene on the surface of the ball. More lights create smoother shadows which more closely resembles GI lighting.