Texturing

TIFF image textures should be used here. Even though there are going to be many procedural shaders built for this project, any textures used for maps can only be TIFF format, the texture processor cannot accept any other kind of format.
This is also helpfull to start with TIFF format in Blender because Blender cannot erase datablocks that formally held texture maps in them, something that really is NOT a huge deal in the final stages of rendering but during export from Blender it does take up a second or two of time to just report that Teqser cannot handle that format.

http://wiki.aqsis.org/doc/display#file_tiff

OpenEXR can also be used for texture maps, though they serve more use as environment maps rather than material texture maps, since exr is an HDR file format. These can also be used for Image Based Lighting, though I am pretty sure Aqsis does not handle that kind of rendering procedure (??). In this short this might actually come in very handy for things like reflections, which in most rendering applications is done by ray tracing. When RenderMan was first designed, reflections were done by image based reflection mapping since PRMan did not do ray tracing until much later during the late 1990's (due to increased speed and power of hardware). Using reflection maps certain scenes, like close ups of the spider's face, these maps can add a level of realism that we are looking for.

http://wiki.aqsis.org/doc/display#exr

Texture maps can be any size, since it does get MIP processed in the end, however depending on the map needed make best judgement to pixel size. However due to the size of TIFF, until LARGE scale data storage can be utilized keeping only those textures absolutely needed in the project folder should be enforced. Most TIFF images can reach a 5MB size each and some can be 2-3 times larger.

For a single model multiple textures can be used and while that model may not contain a lot of mesh data, the image data can easily reach 50 MB. Teqser will convert these TIFF's into MIP maps, which are also larger due to the functioning of the MIP map so while a TIFF may be 12 MB in size, the TX file can be 16 MB when fully processed. This can easily eat up hard drive space, so again to conserve space at this time, use only what is NEEDED on the project folder and WIP files kept on your own drive, simply copy the image over to the project folder when complete.

Depending on the scene and complexity needed, shaders will be used instead of textures. This again reduces the rendering time needed.

When texture maps are considered complete, they will be exported as processed MIP maps. During the animation stage, exporting and compiling of texture and shader assets will only be exported one time to reduce the export time of each shot. Eric will provide a detailed explanation of that process soon.

Using GIMP to create the image maps for the spider model, the layered image format xcf file should be kept in a local directory, while the output TIFF is saved in the project directory. This saves space, yet the final result will still be obtainable by others in the project directory.

The texture map directory will consist of both TIFF, EXR and TX (compiled MIP map) texture files. This way ALL working images used in production will remain in one place. Under normal CG production this usually does not seem to be the case, instead these maps are placed in seperate folders for their respective models. For this instance the central map directory is being used to simplify the process when assets are being rendered.

Blender and Mosaic Texture Handling

In Blender images can be saved either as a file path or "packed" in the project. Once an image is loaded the data exists in the UV editor independent of the original file (this is why the image has to be reloaded when externally edited). In python the image can have several states, it can report a valid file path, it can report an invalid file path, it can report image data in Blender and it can report its packed. MOSAIC looks at this information to determine how to export the images:

1) if image is packed it asks Blender to write the image to the maps folder (always works)
2) if image is NOT packed but has a valid file path it copies the original image file to the maps folder
3) if image is NOT packed and has NO valid file path but Blender has image data it is written to maps folder
4) if none of the above then error

The problem come in on #3, sometimes Blender will report it has image data when it really doesn't. If that happens Blender will export a bogus image file that will not optimize without errors. This usually happens when a image has valid file paths when saved but reopened with invalid file paths. Blender will report the image as valid when it is not, MOSAIC purposely avoids direct file/path access to avoid cross platform problems and instead chooses to trust Blender.

Anyway the only way around this is to either ensure image paths are always correct on all systems or pack the images in the project. One good way to insure proper paths is to use relative non-windows paths like BBB did.
This is done by using / instead of \ and using the home // so path starts where blend file was opened and then ../ to navigate down. For instance if you had a folder "train" with the folders "model" and "maps" where "model" had your blends and "maps" had your images then your image paths would look like "//../maps/myimage.tif". This will work across OS's as long as you start Blender in the folder where the blend is. Also never never use spaces in path and file names, use _ instead such as "my_path_only_thinks_it_has_spaces" :)

Another way of managing images would be to use a link library. Instead of putting images in a folder they could be put in a blend and then "linked" in to each production blend.

Texture Usage

Sometimes texture maps can be used for other purposes other than intended. For instance during the mapping of the spider, the normal map that was generated in Blender didn't give satisfactory results in Aqsis and later during a preview render the thought that using the normal map for specular color came to mind and switched the map to that - the resulting render looked quite interesting and resembled the coloring of the shell of a June Beetle for instance. Since then the spider model is not using the normal map for specular color, just wanted to show this as an example of other uses for different types of maps.

with_normalmap.jpg
normalmap_spec_color.jpg

If you do find a texture map on the web - make sure it is able to be used, there is nothing worse than finding a resource and being sued. ;)

Tools

  • Cinepaint
  • GIMP
  • Photoshop

GIMP or Photoshop (if available) are the tools to make and edit texture maps. In order to get the best quality textures use high resolution images (2048x2048 or higher). Since there will be closeups on geometry this is almost a necessity. Depending on the shot and model, it will be determined whether just a shader or texture map will be used. If a model is too far away for details to be seen, a shader will be the most cost effective solution since it does not require Aqsis to eat CPU cycles to render the MIP map. However if the camera is close to a model it might need that texture.

Cinepaint should be used more than GIMP, even for texture maps because of the amount of color data that it can handle. GIMP cannot handle color ranges for film, including HDR files. Cinepaint is typically used for post production work, however due to some texture map issues there is a growing urge to use Cinepaint for ALL image work.
The ONLY issue with using Cinepaint is that it is primarily developed for Linux, the Windows version is several years old already. While using Cinepaint on older Windows builds is ok for texture work, there is no support for HDR formats like OpenEXR (which is the final frame output we are using).

It is quite ok to use other programs to make textures as well, just remember these points :

  • TIFF is the ONLY format Aqsis can create optimized MIPMaps from
  • 2048x2048 pixel resolution should be the absolute minimum size
  • Do not save textures in lossy formats (JPEG)

Another tool that I have known about but have not actually used much is called MapZone 2, which is available free. With this one can build prefectly repeatable textures without having to resort to some painfull cloning. The software uses a node like building structure, similar to Shaderman and Blender nodes, to build textures from the ground up. While on one hand this can come in handy, on the other hand I have not used it much so the look of textures might not match up to quality standards we are used to with photos or procedural shaders. Depending on the situation I might give it a try.

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License