C++ / ObjectARX Developer for AutoCAD 3D Tools

I’m looking for an experienced C++ developer with strong ObjectARX knowledge to enhance and maintain custom 3D modeling tools inside AutoCAD. The work is focused on improving existing functionality rather than building everything from scratch.
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Scope of work includes:
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Improving and extending custom 3D modeling features inside AutoCAD.
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Debugging and fixing issues in an existing AMEAPI-based codebase that currently runs in AutoCAD 2022.
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Updating face-selection functionality (ap_sel_face or similar) so it works reliably with shaded 3D solids, with proper cursor/face feedback.
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Ensuring compatibility and smooth behavior in modern AutoCAD environments, and preparing the code for future updates if needed.
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Requirements:
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Strong experience with C++ and Visual C++.
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Proven ObjectARX / AutoCAD plugin development experience (please share examples).
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Solid understanding of 3D geometry and CAD concepts.
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Ability to read, understand, and refactor existing code.
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Nice to have:
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Experience with ProgeCAD or similar AutoCAD-compatible platforms.
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Familiarity with AMEAPI or legacy AutoCAD 3D APIs.
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Project details:
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Engagement: Less than 30 hours per week to start.
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Duration: 1–3 months, with potential extension based on results.
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Please include in your bid: a brief summary of your ObjectARX experience, examples of similar AutoCAD/CAD tools you’ve built, and your availability (hours per week, time zone).