Hi guys, I am working on some mesh scripts and in evaluations of the vertices I wanted to coerce a point to check against, and then discovered that the vertex is vastly simplified compared to the coerced 3d point of that same vertex, why is that??? It seems very wrong that the mesh returns a lesser …

I recorded RH-58628 to keep track of this problem. Right now, users can use the mesh.Vertices.GetPoint3dAt() function to look at the double precision vertex of the mesh. This is however a little less easy to find than the indexer [], which returns the single precision.

From the Python floating point tutorial perhaps my favourite bit is this: print ( 0.1 + 0.1 + 0.1 == 0.3) Just paste that in EditPythonEditor and run it :slight_smile:

[image] nathanletwory: print ( 0.1 + 0.1 + 0.1 == 0.3) [image] Ok, I am logging off and will stare at the sky for a while. My world just crumbled.

Welcome to the wondrous world of programming!

[image] piac: This is however a little less easy to find than the indexer [] , which returns the single precision. OK so I guess that with my new “knowledge” it refines to a wish: I wish that the coerced 3D point of the single precision indexed point results in the same value as the printed …

[image] Holo: I wish that the coerced 3D point of the single precision indexed point results in the same value as the printed value of that given point. Printing single precision, as you can see, has less accuracy than double precision. We can’t have the indexer return doubles now, because i…

:grimacing: I don’t know anyting any more… Nathan just broke my mind… A = (0.1+0.1+0.1) B = 0.3 print A == B It’s False… Hahahahahaaa…

Give it a few days :slight_smile:

[image] Holo: If it was just a bunch of 00000 filling up the space Maybe that is what happens to the binary value. And then the same (binary) number is simply formatted as decimal using different precisions … … I guess since one is a 32 bit value and the other a 64 bit value. EDIT: [imag…

Mesh.Vertices accuracy seems wrong, why?

Scripting

piac (Giulio Piacentino) May 19, 2020, 1:40pm 18

You may want to use the “r” (roundtrip) format specifier:
https://docs.microsoft.com/en-us/dotnet/standard/base-types/standard-numeric-format-strings

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Mesh.Vertices accuracy seems wrong, why?

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