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AndreiBarsan / DynSLAM

Master's Thesis on Simultaneous Localization and Mapping in dynamic environments. Separately reconstructs both the static environment and the dynamic objects from it, such as cars.
BSD 3-Clause "New" or "Revised" License
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Raycasting for fusion = possible reason for artifacts in e.g., road #22

Closed AndreiBarsan closed 7 years ago

AndreiBarsan commented 7 years ago

See Nießner et al., 2013, near end of Section §5: "In an idealized case, each depth sample would be modeled as an entire frustum rather than a single ray. We would then allocate all voxel blocks within the truncation region that intersect with this frus- tum. In practice however, this leads to degradation in performance (currently 10-fold). Our ray-based approximation provides a balance between performance and precision. Given the continuous nature of the reconstruction, the frame rate of the sensor, and the mobility of the user, this in practice leads to no holes appearing between voxel blocks at larger distances (see results and accompanying video)."

In their case, given the range of the kinect sensor, there are no artifacts in the map. For us, however, this may be the reason why we're seeing the artifacts in the ground, especially when we set the max depth relatively high (e.g., 20m).

To solve this, although nontrivial, we could try casting multiple rays when e.g., allocating the depth frame for z values > something.

AndreiBarsan commented 7 years ago

Nontrivial, and not relevant to thesis. Closing for now, but it's good to keep in mind!