Hi Apple Team,
I’m working on a human portrait scanning application using PhotogrammetrySession, and I’ve been very impressed by the results. Thank you for building such a powerful and accessible photogrammetry solution into macOS!
I do, however, have a question regarding mesh detail limitations on different Mac hardware configurations.
When using PhotogrammetrySession.Request.Detail.custom and trying to set maximumPolygonCount = 1000000, I see the following log message:
Clamped max poly count: 1000000 to device limit. 250000 is used.
This is on an M1 Max with 32 GB RAM.
I’m aware that PhotogrammetrySession.limits can report values like maximumInputImageDimension and maximumNumberOfInputImages, but I haven’t found documentation on how the maximumPolygonCount is determined, and what hardware specs influence it.
Is it tied more to:
• GPU performance (e.g. neural/graphics cores)?
• CPU architecture?
• Memory size or bandwidth?
• Or is it fixed per SoC generation?
I’d love to understand what kind of hardware upgrades (e.g. moving to M4 Pro or increasing RAM) could allow me to increase mesh complexity and generate more detailed models.
Any insights would be greatly appreciated—and if this is covered in upcoming WWDC sessions or documentation, I’d be happy to tune in.
Thanks in advance!
KitCheng
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Hi Apple Team and Developers,
First of all, I’d like to express my appreciation for the incredible results achieved using PhotogrammetrySession. I’ve been developing a portrait scanning app using Object Capture, and in many tests—especially with human models—I’ve found the reconstructed body surfaces are remarkably smooth and clean, often outperforming tools like Metashape and RealityCapture in terms of aesthetic results.
However, I’ve encountered some challenges when working with complex areas like long hair overlapping the face. For instance, with female models where strands of hair partially occlude the face, the resulting mesh tends to merge the hair and facial geometry. This leads to distorted or “melted” facial features, likely due to ambiguity in the geometry estimation phase.
Feature Suggestion:
Would it be possible to allow developers to supply two versions of the input images:
• One version (original) for texture generation
• A pre-processed version (e.g., contrast-enhanced or CLAHE filtered) to guide mesh reconstruction only
This would give us the flexibility to enhance edge features or shadow detail without affecting the final texture appearance. In other photogrammetry pipelines, applying image enhancement selectively before dense reconstruction improves geometry quality in low-contrast areas.
Question:
Is there any plan to support this kind of two-path workflow in future versions of PhotogrammetrySession? Or perhaps expose more intermediate stages or tunable parameters to developers?
Also, any hints on what we can expect from WWDC 2025 regarding improvements to Object Capture or related vision/3D technologies?
Thanks again for this powerful API. Looking forward to hearing insights from the team and other developers.
Warm regards,
KitCheng