Access & attribution
Accessibility & media credits
The design target is WCAG 2.1 Level A and AA.
This author-maintained research site uses semantic HTML, a neutral palette, keyboard-operable controls, and descriptive alternatives for research media. Automated checks are part of the deployment workflow; they do not establish complete ADA or WCAG conformance.
Using this site
- The first keyboard link skips to the main content. Keyboard focus is visible throughout the page.
- Silent videos play and loop when visible unless reduced motion or data saving is enabled. Each video’s native controls allow you to pause or resume playback. Manual pauses are remembered when scrolling, and offscreen videos pause automatically.
- Short field and laboratory clips are distributed across the page. Each retains its original speed, has no audio track, and includes a complete text alternative and timed WebVTT descriptions.
- The opening shows two silent videos side by side, a roofer on the left and the robot on the right, with no text over them; the title sits below. Native fullscreen controls remain available.
- Laboratory clips show selected movements from independent recordings. They are cropped to the robot, so the safety tether stays in view and the operator stands just outside the frame, and they end before later falls or resets. Each description identifies the source and visible action; these clips do not show complete trial outcomes or independent roofing work.
- Paper figures have descriptive alternatives and longer explanations. The page presents the method and observed movements visually; the original paper contains the quantitative evaluation.
- At narrow widths, content reflows into a single column. BibTeX text scrolls within its own focusable area.
- Core content, native video controls, and full text alternatives remain available without JavaScript.
Paper & figure accessibility
This website presents selected content from the roofing paper on arXiv. Descriptions accompany the displayed figures and videos. For the complete study, arXiv also provides an experimental HTML rendering of the preprint.
The supplied manuscript PDF is untagged and remains unchanged. We have not verified the external PDF’s tags, reading order, mathematical accessibility, or assistive-technology behavior. The HTML rendering is an additional reading option, not a certified accessible version.
Checks and remaining review
The repository includes an axe-core check against WCAG 2.1 A/AA rules, plus checks for keyboard navigation, media behavior, image alternatives, 320 CSS-pixel reflow, text spacing, and content with JavaScript disabled. A failing check blocks automatic deployment. See the deployment checks and the review record.
The current verification record covers motion preferences, autoplay, pause persistence, media alternatives, and the responsive page layout. Recorded automated results apply only to the revision tested.
Automated coverage is limited. A full review with multiple screen readers, users with disabilities, and accessibility specialists remains outside the completed technical checks. This page does not claim an ADA or WCAG certification.
Report an access barrier
Email Songyang Liu at liusongyang@ufl.edu. Please include the page, the content you need, and the browser or assistive technology involved so we can help provide a usable format.
Privacy
This static site loads its fonts, figures, and research-team video clips locally. It uses no analytics, advertising, or embedded third-party players. Following an external link opens the provider’s site, where that provider’s privacy practices apply.
Recorded by our team
Video descriptions & sources
These independent excerpts play silently at original speed when visible, unless reduced motion or data saving is enabled. Use each player’s native controls to pause or resume. Manual pauses are remembered when scrolling. Laboratory clips are cropped to the robot: the safety tether remains visible, and the operator stands just outside the frame.
Roofing fieldwork
Source: Research team · Self-recorded roofing field footage
Roofer at work
A silent film of three shots at original speed, shown beside the robot. On an unfinished pitched roof, a worker carries a sheet of sheathing across the slope, bends over it with a handheld tool, and lowers into a deep crouch with both feet on the slope. Timber framing, neighboring houses, trees and sky are in view. This is field footage recorded by the research team.
Source: the research team’s original field recording, IMG_7082 (1).MOV, IMG_7081.MOV, IMG_7082.MOV and IMG_7085.MOV. Web excerpts use its silent browser viewing copy. Original recordings remain unchanged.
Opening film
A silent film of two shots at original speed, shown beside the roofer. In a laboratory, a Unitree G1 humanoid on a padded incline bends and lowers a handheld tool toward the pad, and in a separate trial bends deeply toward the surface. A safety tether is attached. The frame is cropped to follow the robot; the operator holding the controller stands just outside it. The robot shots end before later motion, falls, or resets and do not show fastening.
Source: the research team’s field recording and the authors’ laboratory recording, bending_real_test_20260905_185804_260763_nailgun.mp4. Excerpts are joined with hard cuts at original speed.
Paper figure 4
Figure 4 begins with PICO VR motion tracking. Human motion is extracted and retargeted to the humanoid. The motion prior, a metric roof mesh, and task semantics enter contact/phase inference, roof-frame registration, and whole-trajectory refinement. This step adjusts foot support, work clearance, and body-surface nonpenetration while preserving motion and smoothness. In simulation, reference motion, proprioceptive state, and terrain information guide policy learning. The final stage shows physical locomotion and working postures. Execution-aware rewards help maintain the intended spatial relations during tracking.
Source: Liu and Li, arXiv:2609.20558v1, figure 4, PDF page 14. Original scientific artwork and colors retained.
Roofer and G1 pairs
Uphill walking
Left, a roofer carries a sheet of sheathing up a pitched roof. Right, a Unitree G1 humanoid walks from the floor onto a padded incline. The two halves come from separate recordings shown side by side, so their motions are not synchronized. The roofer footage is mirrored so both face the same way. The robot is in a laboratory with an overhead safety tether attached, and the frame is cropped so the operator holding the controller stands just outside it. The robot excerpt ends before later motion, falls, or resets and does not show fastening. Silent, at original speed.
Source: IMG_7081.MOV (left), g1-roofing-walking-centered.mp4 (right).
Bending
Left, a roofer stands at the roof edge and bends down to reach a sheet of sheathing passed up from below. Right, a Unitree G1 humanoid bends deeply toward a padded incline. The two halves come from separate recordings shown side by side, so their motions are not synchronized. The roofer footage is mirrored so both face the same way. The robot is in a laboratory with an overhead safety tether attached, and the frame is cropped so the operator holding the controller stands just outside it. The robot excerpt ends before later motion, falls, or resets and does not show fastening. Silent, at original speed.
Source: IMG_7081.MOV (left), bending_real_test_20260905_190338_973040.mp4 (right).
Nailgun positioning
Left, a roofer bends over the sheathing with a pneumatic nailer close to the surface. Right, a Unitree G1 humanoid steps forward on a padded incline, bends, and lowers a handheld tool toward the pad. The two halves come from separate recordings shown side by side, so their motions are not synchronized. The roofer footage is mirrored so both face the same way. The robot is in a laboratory with an overhead safety tether attached, and the frame is cropped so the operator holding the controller stands just outside it. The robot excerpt ends before later motion, falls, or resets and does not show fastening. Silent, at original speed.
Source: IMG_7085.MOV (left), g1-roofing-tool-centered.mp4 (right).
Hammer positioning
Left, a roofer takes a hammer from the tool belt, bends over the sheathing, and strikes near its edge. Right, a Unitree G1 humanoid steps forward and bends deeply, bringing its hand and tool close to the padded surface. The two halves come from separate recordings shown side by side, so their motions are not synchronized. The roofer footage is mirrored so both face the same way. The robot is in a laboratory with an overhead safety tether attached, and the frame is cropped so the operator holding the controller stands just outside it. The robot excerpt ends before later motion, falls, or resets and does not show fastening. Silent, at original speed.
Source: IMG_7082.MOV (left), robot-hammer-centered.mp4 (right).
Excerpts illustrate selected supervised movements, rather than complete trials or independent roofing work. They end before later falls or resets. Source recordings remain unchanged; the original paper reports the experimental evaluation.
Research figure credits
Selected figures come from the user-supplied arXiv preprint by Songyang Liu, Shuai Li. Figure numbers and descriptive explanations accompany the figures on the project page. Original third-party credits remain in the source paper. Rights in research papers and third-party media remain with their respective holders.