Copyright (C) 2011-2017 mailto:[email protected]
dexvt-lite is a 3D inverse kinematics and GPU ray tracing tech demonstrator. It features rovolute joint constraints, prismatic joint constraints, end-effector orientation constraints, and... GPU ray tracing!
See sister project demonstrating other engine features: dexvt-test
3D Inverse Kinematics
Supports rovolute joint constraints, prismatic joint constraints, and end-effector orientation constraints. The way each constraint type is handled is described below:
-
Revolute Joint Constraints
- "Non-hinge" joints
- In each joint's rotation step, rotate on a pivot that aligns the end-effector with the target.
- Enforce joint constraints in euler space by capping the post-rotation orientation of the adjacent segment to be within the joint's maximal deviation from neutral orientation. Do this for each axis.
- "Hinge" joints
- In each joint's rotation step, rotate on a pivot that minimizes the distance between the end-effector and the target, all the while staying within the joint's plane of free rotation. Setting non-constraint-violating goals early on avoids most problems described here.
- Enforce joint constraints perpendicular to the joint's pivot by squeezing the post-rotation orientation of the adjacent segment to be within the joint's plane of free rotation. This adds numerical stability to the pivot so it doesn't "drift".
- Enforce joint constraints within the joint's plane of free rotation by capping the post-rotation orientation of the adjacent segment to be within the joint's maximal deviation from neutral orientation.
- "Non-hinge" joints
-
Prismatic Joint Constraints
- In each joint's translation step, slide the adjacent segment by the maximal extent it can slide within the joint's range of free translation to align the end-effector with the target.
-
End-effector Orientation Constraints
- In each joint's rotation/translation step, extend the end-effector position by the end-effector orientation offset.
GPU Ray Tracing
-
Supports 4 material types:
- Reflective
- Transparent
- Diffuse
- Glowing
-
Supports 3 primitive types:
- Spheres
- Planes
- Boxes
Unix tools and 3rd party components (accessible from $PATH):
gcc mesa-common-dev freeglut3-dev libglew-dev libglm-dev libpng-dev curl imagemagick
Resource files not included:
| resource files | purpose |
|---|---|
|
data/SaintPetersSquare2/posx.png data/SaintPetersSquare2/negx.png data/SaintPetersSquare2/posy.png data/SaintPetersSquare2/negy.png data/SaintPetersSquare2/posz.png data/SaintPetersSquare2/negz.png |
Cube map texture (6 faces) |
| data/chesterfield_color.png | Color map texture |
| data/chesterfield_normal.png | Normal map texture |
| target | action |
|---|---|
| all | make binaries |
| test | all + run tests |
| clean | remove all intermediate files |
| lint | perform cppcheck |
| docs | make doxygen documentation |
| resources | download resource files |
| clean_lint | remove cppcheck results |
| clean_docs | remove doxygen documentation |
| clean_resources | remove resource files |
Keyboard:
| key | purpose |
|---|---|
| b | toggle bounding-box |
| f | toggle frame rate |
| g | toggle guide wires |
| h | toggle HUD |
| l | toggle lights |
| n | toggle normals |
| p | toggle ortho-projection |
| t | toggle texture |
| w | toggle wireframe |
| x | toggle axis |
| z | toggle labels |
| up/down | pitch |
| left/right | yaw |
| pg-up/pg-dn | roll |
| home | toggle target |
| space | toggle animation |
| esc | exit |
Mouse:
| mouse-button + drag | purpose |
|---|---|
| left | orbit |
| right | zoom |
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- "Ray-Sphere Intersection"
- https://www.scratchapixel.com/lessons/3d-basic-rendering/minimal-ray-tracer-rendering-simple-shapes/ray-sphere-intersection
3D inverse kinematics (cyclic coordinate descent), forward kinematics, rovolute joint constraints, prismatic joint constraints, end-effector orientation constraints, GPU ray tracing