【转帖】vectorisation Problem With Direc
 

vectorisation problem with directx
vectorisation problem with directx
hi, i'm working on a cad application using oda.
i'm trying to improve vectorisation.
i prefer directx engine for many reasons.
but...
i finded a case where directx (and opengl) seems to be lost.
i think it's a problem of coord. transformation between oda and directx...
look at these 2 examples.
the only difference between the 2 files is the ellipse inserting point coord.
please answer me (and probably excuse my english).
attached files

you are right - the problem is in coordinates transformation.
both opengl and directx devices stores world cache in float coordinates (interface of directx can't accept doubles, our opengl device implemented using doubles, but it works internally through floats). ellip arc have too much y-coord value, camera have similar value. so transforming from world to eye space leads to precision lost.
we'll think what we can do with such problems. btw, opengl device with caching turned off renders both samples successfully.
sincerely yours,
george udov