Game Development Reference
In-Depth Information
Benefits of conformance include highly interoperable tools, credibility and good will, protection against product
regression, easy-to-create use cases, streamlined procurement, clear customer expectations, and consistency of
implementation with other vendors, not to mention happy and productive users.
In this chapter, which is based upon The Khronos Group's current COLLADA CTS Tutorial, we explain how to
use the suite to build a rock-solid 3D content pipeline, saving a huge amount of time in the development of tools
and games.
The tests may be used on one target application alone for both conformance and regression testing, or to verify
interoperability between one application and another, such as Trimble SketchUp (formerly a Google product), Autodesk
3ds Max, and Autodesk Maya. There are 613 tests and three possible levels of conformance (badges)—Baseline, Superior,
and Exemplary—but regardless of the application's capabilities, all the tests must be run. Based on the results, the
framework determines which, if any, badge to award.
The conformance tests can be used on two types of applications: import only and import/export. Import-only
applications include 3D document viewers, game engines, ray tracers, and rendering packages. Import/export
applications include most traditional content creation tools that do modeling and animation. Both classes of
applications must be able to render COLLADA data as an image because that is the primary method the CTS uses
to determine whether a COLLADA document has been correctly understood. For a complete test, the software must
also be able to import and export COLLADA documents. You can test applications that support only some of these
functions, but they can only earn conformance within the context of a conformant implementation environment
(i.e., one that has already passed the test suite) that provides the missing functionality.
The suite tests whether the target application does the following:
•
Handles COLLADA input and output properly
•
Renders files created under different conditions consistently
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Outputs COLLADA documents that conform to the COLLADA schema
Some of the issues tested are
•
Completeness of support for each feature
•
Robustness when bad data is encountered
•
Appearance of images and movie clips
•
Preservation of features during a load/save cycle
Types of tests include
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Minimal unit tests for specific features, like document referencing and skinning
•
System tests that exercise desirable common scenarios, such as skinned rag doll export/
import with COLLADA FX materials on different body parts
•
Stress tests for very large scenes
•
Handling of local or temporary test data
•
Handling of invalid or corrupt data
All importers must be able to read any valid COLLADA document without failure, even if that document contains
features not supported by the importer. Features beyond the importer's level of support are not required to be
understood, but simply encountering them should not cause the importer to fail. Unusual or unexpected ordering or
quantity of elements should not cause an importer to fail as long as the document validates to the schema. For example,
library elements may occur in any order and libraries of the same type can appear multiple times. Importers must not
require their own COLLADA extensions in order to understand valid documents.
