Slide 1 - COFES.com
Download
Report
Transcript Slide 1 - COFES.com
VideoTrace: Interactive
3d modelling for all
Anton van den Hengel
Director, Australian Centre for Visual technologies
Associate Professor, Adelaide University, South Australia
Director, PunchCard Visual technologies
Input
Modelling
Results
Interactive 3D modelling
3D modelling is critical to all sorts of application
Special
effects, but also mining, architecture, defence,
urban planning, …
People are getting more visually sophisticated
More 3D data is being generated
More
cameras, but also scanners etc
The interfaces of modelling programs are
usually very hard to fathom
Why?
Insert your own objects into a game
Put your couch into second life
Model your house for Google Earth
Video editing
Cut
and paste between sequences
Remove someone from your home videos
Put your truck into a game
Put your truck into a game
Modelling for animation
Video editing requires models
Dense surface reconstruction
Video editing requires models
Structure from motion
The process
Capture and import the video
Perform
structure and motion analysis
Interact with the system to generate and
edit the model
Export to your application
The approach
Pre-compute where possible
Structure
from motion (camera tracking)
Superpixels
Then interact
Interactions
results
allow user to exploit precomputed
Structure from motion
Camera tracking
Calculates
Reconstructed
point cloud
Camera parameters
Location
Orientation
Intrinsics (eg. Focal length)
Informs interaction interpretation process
Interactive modelling from video
Interactions
Straight lines
Closed
sets of lines define planar polygons
Curves
For
planar shapes with curved edges
For NURBS surfaces
Mirroring
Duplicates
Extrusion
existing geometry
Fitting planar faces
User specifies boundary
Boundary specifies infinitely many planes
Similar to pre-emptive RANSAC
Generate
bounded plane hypotheses from
point cloud
Eliminate hypotheses that fail a series of tests
Run simplest / most robust tests first
Generally 3d tests before 2d tests
Fitting planar faces
Line of sight
Object points
Image plane
Hierarchical RANSAC
Generate bounded plane hypotheses
Tests
Support
from point cloud
Reprojects within new image boundaries
Constraints on relative edge length and face
size
Colour histogram matching on faces
Colour matching on edge projections
Reprojection is not self-occluding
Curves
Mirroring
Extrusion
Dense surface reconstruction
Needs to be at interactive speed
Calculated as a max-flow graph-cut over a
Markov Random Field
Link cost based on photoconsitency
Modelling without features
Modelling without features
Recent model
Future work
Other interactions
Other data sources
Occluding contours
Interactive SFM
De / Re-lighting