查看单个帖子
旧 2009-05-07, 06:16 PM   #1
yang686526
高级会员
 
注册日期: 06-11
帖子: 14579
精华: 1
现金: 224494 标准币
资产: 234494 标准币
yang686526 向着好的方向发展
默认 【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
yang686526离线中   回复时引用此帖
GDT自动化论坛(仅游客可见)