Models which needed unwrapping to be planned or made under specific requirements. These were parts of the hull:
3.1 Shroud. Lines of the texture needed to be parallel with seams on the hull; therefore the proportions and contour on the unwrapping were to be the same on the hull and its parts. These requirements, for instance, excluded the use of Pelt mapping (Fig.12a - b).
3.2 Tray. There must be some relief on the plate on the bottom of the hull. The easiest way to make this relief is by using Displace. As the relief's pattern should be balanced along the hull, I needed to use planar mapping on the displaced part to preserve its contour and proportions, and to build up the rest of the mapping around it, avoiding texture distortion and hiding the seam which was achieved by using Pelt Mapping, Relax and handmade vertex positioning (Fig.13).
The materials could also be divided in two groups, as follows:
Standard. In most cases these are enough to achieve simple tasks. The basic principle is to achieve the goal by playing with basic material settings, using textures for the slots of Diffuse, Reflection, Glossy and so on, and corrections of these textures by means of the texture's Output menu (or by means of plug-ins like Colour Correct http://www.cuneytozdas.com/software/3dsmax/) (Fig.14a - b).
Composite. These are used in specific tasks, built up on combinations of different materials or textures by means of masks or Procedure maps. They have "branchy" hierarchy. A striking example in this work is the ground material.
Formerly, all the textures were prepared in Photoshop. In the material editing I used finished images that were received from the Photoshop output. If I needed to edit the texture, I returned to Photoshop. Exceptions to this were in cases when only the contrast should be changed - instead I used curves in the texture's Output menu for it. It's a standard approach which lets you edit materials without complicating their structure, and in the beginning i wasn't intending to digress from using this.
To begin, I needed to define the resolution of the texture that I had to work with. There was no sense in making a unique drawing of the texture for the whole object, as it would be partially hidden by other models. Besides that, at this stage I was working in 32-bit WinXP and was restricted by 2GB RAM for a programme. I wrote "3gb" in boot.ini and it gave me a little space to act, but I still needed to use memory sparingly. So, when the unwrapping was done, I scaled it in such a way that 3ds Max's unwrap projection contained only these parts that could be seen in two views minimum. This way I got a square with the model of the bike in the centre of it - this square didn't cover all visible ground areas which led to texture tiling, but as it didn't fully appear in the field of view of any camera in the scene, tiling wouldn't be visible as the tiled part of the texture was outside of the screen, or hidden beneath the environment (Fig.15a).
With the texturing region determined I then moved onto the resolution. To define this, I used a 1000x1000 pixel texture for the object, with which I intended to imitate the ground and made some renders in final resolution, increasing the tiling until aliasing disappeared. The figures I got looked bad - the tiling measure increased to 12. This meant that I needed to use a 12000x12000 texture to get a decent picture of ground, but at the time 3ds Max crashed when I tried to use textures larger than 4096 pixels on the largest side.
One thing I could do was to assemble the needed texture from smaller ones inside 3DMax, like this:
- I took some textures of tarmac, rocks, earth, mud and sand
- I set the textures' scales to the scene scale by setting the tiling measure for each one of the textures
- I made lighter and darker variants for each texture
This way I got about 30 layers which I needed to blend with each other to "break" the tiling effect of each layer and to remove the synthetic uniformity it made, making the final texture more natural-looking and credible. Following the same principle I also made sure that the tiling effect of textures with the same resolution had different values, so that seams between the tiles on different layers didn't lie in the same places. Then, using the Mix map, I began to blend the layers.
In the beginning I intended to use procedure maps as masks, but I wasn't satisfied with the result and decided to use textures. I was limited in their maximum resolution as before, but as they were used to mark the sections of layer mixing, they could be stretched without risk of worsening the final image, as the scale of the layers remained the same. Cheating it is, and it led to some artefacts, but they were easy to remove with the Healing Brush in Photoshop (Fig.15b - d).
< previous page next page >