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Gaussian Splatting · 11 Value Decoding and Validation
Series contents · Technology map
Stage: File Validation and Viewer Integration · Editable example · Storage ID: gaussian-splatting-step-11
Goals and learning outcomes
- Distinguish stored values from rendering values.
- Report decoding errors with their locations.
Prerequisites
Continue using the output and records from Unit 10. Before the Value Decoding and Validation experiment, preserve the previous inputs and reference outputs.
Key concepts and explanations
Activation functions
Training files may store scale or opacity in a transformed space. Apply reconstruction functions such as exp and sigmoid only after checking the file producer's convention.
Abnormal values
Nonfinite numbers can break sorting and projection. Check ranges and quaternion length even after conversion.
Practice setup
First check the execution scope guidance on the example screen. The following describes the environment needed to extend the assignment in a separate project. This is a document-guided exercise in a separate local project. Use only small data you create or local files whose usage permission you have checked. The existing preview is a CPU teaching viewer for .splat/ASCII GS PLY files of at most 1 MiB and 512 items; it is not a Spark GPU renderer.
The linked example is a starting point. It does not implement every task below. Complete work beyond its supported scope in a separate project.
Practice tasks
- In decode.js, write a function that accepts an encoding setting and reconstructs scale and opacity.
- Put the same actual scale into raw and log-scale fixtures and compare decoded results.
- Supply NaN, very large values, and a 0 quaternion, and print errors containing the field locations.
Variables to observe
| Variable | Baseline | Change | Expected change / hypothesis |
|---|---|---|---|
| scale encoding | raw 0.1 | log(0.1) with the log setting | Expect both inputs to reconstruct the same scale. |
Predictions in this table are not measured results. Change one condition at a time and record why the actual result differs.
Completion criteria
- The two decoded results differ by at most 1e-6.
- Reject the three invalid values before rendering.
Self-check
- What happens if sigmoid is applied again to opacity that has already been transformed?
- Where should the file producer's convention be recorded?
Official references
Linked example and execution scope
Example source · Runtime environments and limits
CPU Canvas2D synthetic fixtures and contract checks. This does not provide Spark GPU rendering, training data, or claims about reconstruction quality or GPU performance.
Source code and records are not overwritten automatically. Resetting an existing example also preserves your notes.
Next learning
Previous: Checking PLY Headers · Next: Spherical Harmonic Color