Inverse Kinematics for Stretchable Character Bones
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Solution Overview
Problem
Current computer game technologies struggle to realistically simulate characters with stretchable body parts, as existing methods for inverse kinematics do not efficiently handle the stretching or contracting of bones, leading to complex and time-consuming algorithm development and code updates.
Innovation Solution
The method involves performing inverse kinematics operations to determine the updated pose of a character's body part by changing the length of bones, generating virtual joints, and using forward kinematics to bind polygons to these joints, allowing for efficient generation of realistic stretchable body parts with reduced complexity and time in code development.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If inverse kinematics is performed using traditional fixed-length bone methods, then the character skeleton can maintain structural integrity, but the character cannot achieve realistic stretchable body part movements
Solution Approach 1:
The patent applies dynamics by making the bone lengths variable rather than fixed. The inverse kinematics system dynamically adjusts bone lengths based on the desired end effector position and the character's body part pose, enabling stretchable movements while maintaining computational efficiency through structured approach to length modification
Solution Approach 2:
The patent segments the character's body parts into independent skeletal components with base joints and bones that can be manipulated separately. This segmentation allows the inverse kinematics system to adjust individual bone lengths without affecting the entire skeleton, reducing overall algorithmic complexity while enabling localized stretchable movements
2Reliability
If new algorithms are developed to handle stretching and contracting of bones, then realistic stretchable character simulation is achieved, but development time and code complexity increase
Solution Approach 1:
The patent creates a universal inverse kinematics framework that handles both traditional rigid body movements and stretchable bone transformations through a single unified algorithm. This multi-functionality eliminates the need for separate algorithms for rigid and stretchable movements, reducing development time while maintaining simulation reliability
Solution Approach 2:
The patent changes the parameter space of the inverse kinematics system by introducing variable bone length as an additional degree of freedom. Instead of developing entirely new algorithms, the system modifies existing IK parameters (adding length variation capability) to achieve stretchable movements, thereby reducing development complexity
3Ease of operation
If bone lengths are changed during inverse kinematics to achieve end effector position, then stretchable body part movement is enabled, but the computational process becomes more complex
Solution Approach 1:
The patent performs preliminary calculations to determine optimal bone length adjustments before executing the final pose transformation. By pre-computing the relationship between desired end effector position, base joint pose, and required bone length changes, the system simplifies the main computational process while maintaining ease of position control
Data Source
AI summary
Embodiments relate to generating a character with a stretchable body part in a computer game. A pose of a body part of the character is received. The body part includes at least one base joint, bones connected via the at least one base joint, and an end effector coupled to one of the bones. An end effector position is received. The end effector position is where an end effector of the body part is to be placed in an updated pose. Inverse kinematics operations are performed to determine the updated pose of the body part by at least changing a length of one of the bones to place the end effector at the end effector position responsive to receiving the pose of the body part and the end effector position.