Archive notice: This article was originally published on July 6, 2017. Links and embedded videos are preserved as part of the historical record.
First of all: A detailed insight was provided in DIGITAL PRODUCTION 03 : 17 in the article “Look at that!”. So anyone who wants to know exactly can order the complete issue here. Here we provide a short summary.
Reflections
Of course, the real-time display of reflections in Cinema 4D’s viewport still has its limits. However, various sky objects are supported. In addition, individual reflection maps can be loaded for each material and used for real-time display in the editor. This is achieved via the “Enhanced OpenGL” function, for which you need a correspondingly powerful graphics card. For everyone else, Cinema 4D simulates the effect on the CPU, which is not quite as fast but is also satisfactory.
If OpenGL is enabled, you can combine various effects via the Options menu of the editor view, which are then to be displayed there in real time. As already mentioned, some compromises have to be made here. However, the preview comes much closer to the final result than was the case in the previous version.
Shadow Play
Shadows in particular help us establish spatial relationships between objects. Without them, it is often impossible to tell whether objects are touching or whether there is a gap between them. Cinema 4D R18 therefore also improves in this
area and offers us so-called SSAO, which stands for Screen Space Ambient Occlusion. This refers to an effect similar to normal Ambient Occlusion, but calculated via the graphics card and only from the perspective of the current camera. The darkening therefore does not really run three-dimensionally around the objects, but from the camera’s point of view the result is still coherent.
However, we must not be dazzled. When rendering, of course, this effect is no longer visible. It is still necessary to use the Ambient Occlusion shader of the post effect of the same name. But there is also something new to report there, because the effect can now also be inverted. Used as a layer mask, we can repurpose Ambient Occlusion and use it to restrict textures or shaders to hard outer edges. For example, scratches can automatically be displayed only where there are particularly sharp-edged corners, which naturally bump or strike things more often than the concealed parts of an object. Used in the luminance channel, the same effect can be used to simulate subsurface scattering.
Displacement
Displacement is the all-purpose weapon of detailed modeling. It is just a shame that, until now, none of it could be seen in the editor. But that is now over. The upgraded viewport also includes an option for tessellation. This means an additionally calculated subdivision of the polygons, generated exclusively via the graphics card. The user defines the amount and distribution of these subdivisions in the material’s editor settings.
Of course, the result of tessellation is not identical to what sub-polygon displacement delivers during rendering, but that is not the point here. Tessellation provides enough virtual points to see a good approximation of the displacement directly in the editor. This works with textures as well as with many of the available shaders.
Completely New: the Thinfilm Shader
Behind this is an effect that primarily serves to color the reflectance channel and makes highlights and reflections shimmer in all the colors of the rainbow. It is intended to simulate the effect that we can observe, for example, on oily or soapy surfaces, such as soap bubbles or a window pane with numerous greasy fingerprints on it. The incoming light is split into the spectral colors there. The effect is therefore closely related to the refraction of light on transparent surfaces, except that the different wavelengths of light are refracted to different degrees.
