ellipsoidal path connections for time-gated rendering...path integral for physically-based rendering...

[1] Tadano, R., Kumar Pediredla, A. and Veeraraghavan, A., Depth selective camera: A direct,on-chip, programmable technique for depth selectivity in photography. In Proceedings of theIEEE International Conference on Computer Vision (ICCV), (pp. 3595-3603).

[2] Pediredla A., Dave A., and Veeraraghavan A. 2019. SNLOS: Non-line-of-sight Scanningthrough Temporal Focusing. 2019 IEEE International Conference on Computational Photography(ICCP).

Adithya Kumar Pediredla1,2, Ashok Veeraraghavan1 , Ioannis Gkioulekas2

1Rice University, 2Carnegie Mellon University

Ellipsoidal Path Connections for Time-Gated Rendering

https://github.com/

cmu-ci-lab/MitsubaToFRenderer

• Launch-and-play image file for Amazon Web Services clouds (ami-28308957).

• Trivially scales on multiple cores, CPUs, cloud clusters

Time = 0.4s Time = 1.34s Time = 1.74s

Stea

dy

stat

eEx

isti

ng

BD

PT

Ou

rs

Gate location 16 ns

Gate location 16 ns

Gate location 16 ns

Proximity detection camera

Time = 1s Time = 5s Time = 5.85 s

Stea

dy

stat

eEx

isti

ng

BD

PT

Ou

rs

Gate location 4 ns

Gate location 20 ns

Gate location23.4 ns

Transients for dynamic scenesPath integral for physically-based rendering

Steady state rendering: Ij =: 𝓅𝜑 ത𝐱 d𝜇(ത𝐱),

≈𝟏

𝒏σ𝒊=𝟏𝒏 𝜑 ത𝐱𝒊

𝒑 ത𝐱𝒊

ത𝐱 → Path, set of ordered vertices

𝜑 → Radiance of the path, includes photometric and geometric light loss

𝜇 → Path Measure (area or volumetric)

𝒑 ത𝐱𝒊 → Probability of path ത𝐱𝒊 that depends on sampling strategy and the measure (𝝁)

Time-of-flight (TOF) renderer

ellipsoidal vertex𝑥𝑒

𝑥𝑠 𝑥𝑐

Ellipsoidal connections for efficient rendering

• LIDAR

• Amplitude modulated continuous wave

5 cm

OursExisting BDPTScene

SNLOS: Non-line-of-sight Scanning through Temporal Focusing [3]

CWAM-ToF with Depth Selective Codes [2]

Ours

time0

Wt

MSE = 0.056 MSE = 0.010

Existing BDPT

References

Acknowledgments:

• Gated Cameras

• Transient Cameras

TOF RENDERING TASKS THEORY TIME-GATED RENDERING SCENARIOS PUBLICLY AVAILABLE SOURCE CODE

RENDERING CUSTOM TOF CAMERAS

Unified ToF Renderer:𝐼𝑗(𝑓) ≔ 𝓅 𝑓 |ത𝐱| 𝜑 ത𝐱 d𝜇 ത𝐱 ; ത𝐱 : path length

• LIDAR: 𝑓 = 𝛿(|ത𝐱| − minI t >0

𝑡)

• AMCW: 𝑓 = 𝐶𝜔,𝜙 |ത𝐱| ; 𝐶: cross-correlation

• Gated/Transient Camera: 𝑓 = rect𝜏−|ത𝐱|

𝑌

𝑥𝑠 𝑥𝑐Pulsed laser

Camera

Frame: 80

Frame: 150Frame: 115 MSE = 0.411

MSE = 0.044

MSE = 0.183

MSE = 0.019

MSE = 0.442

MSE = 0.162