An Introduction To 3D with Lyndon Daniels

Part 1: Gereral Overview

Planning Texture Output

!Media such as web and mobile outputs are not standardized as they are dependant on the end users device capabilities and software renderer. However, if your character is going to be renedered to a video or still image within a website or mobile app, the resolution of the final image or video can still be utalized to determine an appropriate texture size. Despite the final output targeting a non-standardized platform.

It is also worth bearing in mind that although your character might be used in a Full HD wide shot, your character might not take up more than one half of the full frame size such as in a VWS (Very Wide Shot). This situation is particularly common when the focus of the shot is on the environment that the character is in, or if there is a crowd of many characters.
In this case the entire texture resolution of your character need not be larger than the percentage of the region that your character encompasses. For example, if your character only takes up 10 percent of the entire frame at 1920 x 1080, then the entire resolution of your character's bitmap need not exceed 256 x 256 pixels.

iTo arrive at this figure, 10 percent of 2048 is approximately 205 (rounded up).
However, most 3D applications recommend working in figures with a base of 2x. For example, 28 is equal to 256 which is the closest base 2 number to 205.

It's also generally better to round up to the closest base 2 number when dealing with textures as this may or may not increase memory usage but it is certainly less likely to reduce picture quality of the final render.
Regardless, of the aspect ratio of your final output whether it is more square as with PAL or more rectangular as with HD (see the images below), your texture's dimensions will generally equate to an aspect ratio of 1:1.
As previously mentioned it's recommended that both the width and height of your texture are equivelent to base 2 numbers and it is also recommended that both width and height are equal to each other.

There are no hard and fast rules to creating the "correct" sized texture map, but there are certain guidelines one can follow,
  • First make sure your texture map has a width and height that are equal and are base-2 integers (22 = 4, 23 = 8, 24 = 16, 25 = 32 etc ). 3D applications tend to handle even aspect ratios more efficiently i.e. 1:1 and not 4:3 etc.
  • Create multiple texture maps for different shot types when necassary. One for your characters to be used in close-up shots, another for your entire character to be used in wide shots and finally an ultra high resolution texture map for ECU shots.
  • The logical approach to creating varying texture resolutions, would be to start with the highest resolution texture required then down-scale versions of the same texture from your 2D photo-manipulation software.
  • Use the intended output resolution to determine a starting point of how big to make your texture maps. Not all maps need to be 4K as this can potentially slow down the rendering and development process.

The above images demonstrate that careful consideration is required when determining an appropriate texture size in relation to shot type.
The first image demonstrates that the texture applied to the head is clearly intended for a close up shot while the same texture, rendered on the same model, at the same resolution but with a different shot type of ECU (zoomed in on the character's snout, in the following image), reveals unintended, image quality degradation.