The Plasticity creator explains what a geometry kernel is and compares commercial options C3D, ACIS, and Parasolid, describing his months of research and why he chose as he did.
Why Hacker News points people here: Cited in CAD threads as a rare plain-spoken comparison of commercial geometry kernels and their limitations.
“Mentions an interesting video[2] going through the commercial geometry kernel options and their resp. limitations”HN comment, 2023
“Originally it was based on C3D, but he switched halfway through to Parasolid.[0]”
Plasticity author explains switching from C3D to Parasolid kernel.
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Nick Kallen has been working on an BREP based CAD tool with the sort of ease of modeling that things like Blender has. Originally it was based on C3D, but he switched halfway through to Parasolid.[0] It’s amazing the amount of features he has built considering it’s a one person project. It’s worth going through his progress report videos.[1] [0] this video [1] link
RecommendsvirtualritzFeb 2023
“Mentions an interesting video[2] going through the commercial geometry kernel options and their resp. limitations”
Compares commercial geometry kernels and their limitations.
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See also this thread[1] from yesterday which has some interesting comments on the limitations projects based on the OpenCascade kernel face. Mentions an interesting video[2] going through the commercial geometry kernel options and their resp. limitations from the author of [3]. [1] link [2] this video [3] link
RecommendsawhittyMar 2024
“I think his video comparing geometry kernels [0] was posted to HN a while back, but it's worth a watch if you're curious!”
Plasticity creator compares geometry kernels.
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The creator of this app, Nick Kallen, has a nice YouTube channel where he talks about some of the behind-the-scenes work on the project. I think his video comparing geometry kernels [0] was posted to HN a while back, but it's worth a watch if you're curious! [0]: this video
Cites itruevsJun 2025
“Here is a bit on it from the author of Plasticity”
Background on the C3D kernel from Plasticity's author.
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The other "decent" commercial one that can be licensed is C3D (ASCON/АСКОН uses a CAD kernel based on it in КОМПАС 3D) but it is Russian and thus currently "behind sanctions". Here is a bit on it from the author of Plasticity: this video it initially was based on C3D.
