Rounding Errors in primitives?

[Lasse Deleuran]

I'm pretty sure that 1-4ring5.dat is wrong.

But how can we figure out if it is wrong or not? I do not have access to the source code of PrimGen2, and I cannot find any documentation for how the points are computed. 

All I can do for now is to relax the comparisons to allow large errors. 

Not even allowing an error of 0.0001 is sufficient, as 1-4ring7.dat has the following quad:

4 16 8 0 0 7.391 0 3.0614 6.4672 0 2.6788 7 0 0

But using the same computation as mentioned above, I get the following where differences over 0.0001 are highlighted:

4 16 8 0 0 7.3912 0 3.0616 6.4673 0 2.6789 7 0 0




Full transparency. The points of the quad are computed exactly as before by scaling the points of 1-4edge.dat in Javascript:

'1 0 0 0.9239 0 0.3827 0.7071 0 0.7071 0.3827 0 0.9239 0 0 1'.split(' ').map(x => 7*x).join(' ');

'1 0 0 0.9239 0 0.3827 0.7071 0 0.7071 0.3827 0 0.9239 0 0 1'.split(' ').map(x => 8*x).join(' ');