> y pointing down is merely a convenience thing in Lite - the native 3D > coordinate system of Flash 10 has y pointing down, so lite follows suit to > avoid a lot of matrix inverting. However, the main branch of Away3D has > always had y pointing up, as do the majority of 3D engines.
It's what I understood reading some older posts. Thanks for the confirmation. > when considering primitive construction, it is frequently desirable to have > an option that constructs the geometry of a primitive so that in an > untransformed state, the primtive appears upright to the user. if you're is > appearing upside-down, you just need to multiple all the y coordinates you > set in your primitive by -1. when you do this, the object will be turned it's the only solution I found but since I saw a collada or 3DS rendered the same way on Lite or Std, I thought I missed a point But looking at these loaders source after you post this, it seems I missed some difference between Lite and Std version > inside out, so in order for your faces to render on the outside, you'll also > need to invert either all your x coordinates or all your z coordinates to > un-invert your geometry. ohhh.....it's hardest that I think. Got some problem trying to understand the back face culling and the counterclock wise order... if now I have to invert x or z....8( > The yUp property is there to adjust how the standard primitives are > generated. If yUp is set to false, the primitive is generated with its > symmetric axis pointing along the z axis. This configuration can be useful > if you are using lookAt on your primitive, as the axis of the primitive (say > the axis of a cylinder) is what you would consider to be the axis something > uses to point at something else hoo...so it's not only used for model import! I read an interesting post on Blender forum (http://blenderartists.org/ forum/showthread.php?t=126081 fyi) so I thought it was related to 3D softwares. To test if my yUP handling is correct, I so only have to add it to the scene at (0,0,0) and see if it's pointing like the z axis ? > hope this makes things a bit clearer! yes, thanks a lot I have to find more on the yUP/zUp and the back culling throught...but I made a big step to the final goal thanks to you ;) William
