Tom Arah explores the ways in which 3D modelling and bitmap editing can be creatively fused.

The end quality of 3D output depends largely on the application’s handling of materials and, more often than not, this involves mapping imported bitmaps to your objects’ surfaces...

By placing a scanned label on the cylindrical surface of a generic glass bottle, for example, you can instantly turn it into a believable wine bottle while applying a seamless bitmap tile to create a brickwork pattern can instantly turn a flat plane into a realistic wall. Every 3D application relies heavily on such “texture mapping”, but few give it the focus and attention that it deserves. In fact, apart from basic controls over size, position and tiling, most applications provide little more than a generic Load Image command.

MAXON Cinema 4D

At first sight the PC Pro recommended MAXON Cinema 4D 10 (£499 + VAT, free trial available from www.maxon.net) looks fairly typical when it comes to bitmap handling in a 3D environment. The Material Editor’s main Colour channel offers a Texture parameter from where you can open a standard File Open dialog to load a bitmap from disk, optionally mixing this with a flat colour. The resulting material can then be applied to an object or a polygon selection by drag and drop which adds a texture tag to the object. It’s here in the texture tag settings that you can control offset and length and manage tiling. It’s also here that you choose the best projection method (cubic, spherical, cylindrical and so on) to determine how the flat 2D image should be wrapped around the 3D object to avoid visible seams and make the end effect look as natural as possible.

Cinema 4D’s bitmap handling looks fairly typical - at first sight

So far so-so. Look more deeply though and there’s some more impressive power on offer. To begin with, using Cinema 4D’s Content Browser, you can quickly create a catalog in which a folder’s bitmaps are displayed as thumbnails and can be dragged directly onto a blank space in the Material Editor to define a new material’s colour channel. You can also quickly drag your texture to other channels within the Material Editor and Cinema 4D supports texture mapping in no less than ten (diffusion, bump, reflection and so on). Click on the name of the applied texture in the Material Editor and you are taken to a sub-dialog where you can choose a layer from an imported PSD file (meaning that all of a material’s channel textures can be pooled in a single master file), set a sampling method and set the image’s exposure and black and white points to manage contrast.
More functionality comes from the ability to pre-process the bitmap using a range of dedicated shaders: Filter lets you manage hue, saturation, lightness, brightness, contrast, gamma and clipping; Colorizer lets you remap the bitmap’s colours via a gradient; and Posterizer cuts down the number of tonal levels in the image. A particularly important creative option comes from the Fusion shader which lets you combine multiple bitmap textures by managing transparency and blend mode. For maximum power the Layers shader provides all the above power with some other tricks of its own such as independent control over bitmap transforms and distortions. For hands-on interactive control of texture position, size and rotation Cinema 4D also provides dedicated Texture and Texture Axis tools.