Could you explain how your version might differ from the original
version?
The version in the standard library:
computes M = (Projection x Model)^-1
puts world into a homogenous vector V,
with x/y coordinates mapped from screen coords to -1.0 to 1.0
and z coordinate mapped from (0,1) to (-1,1)
w coordinate set t 1
multiplies MxV, with the resulting w coordinate normalized to 1.0
returns that value
I implemented my own version (based on the C GLU library code) and
got substantially the same results (differences less than 1/100th %
off)
On Feb 5, 5:40 pm, Streets Of Boston <[email protected]> wrote:
> I found issues with the gluUnProject as well.
> I wrote a new one for my own app (The Gube) and it works very well. I
> use gluUnproject for tracking 2D finger-touches and flings into the 3D
> model-view/space.
>
> You can do a gluUnproject search on this forum and you will find
> this:http://groups.google.com/group/android-developers/browse_frm/thread/9...
>
> Go to message# 8, which contiains the source control.
>
> On Feb 5, 7:18 pm, Tim Newsham <[email protected]> wrote:
>
>
>
> > Hi, I'm having problems with gluUnProject. I saw other discussions on
> > this message base regarding this function and they did not solve my
> > problem. When I use GLU.gluUnProject I get values that are close, but
> > not quite right. I'm manually keeping track of my model matrix and I
> > replicate the projection matrix manually. (I have also tried setting
> > the projection matrix to identity and manually incorporating a
> > projection matrix into my model matrix, and I ended up with the same
> > results). I tried using the builtin GLU.gluUnProject function and I
> > also implemented my own based on reading that source and reading the C
> > GLU sources and both seemed to give substantially similar results.
>
> > So I put together a small demo, trying to keep it as minimal as
> > possible and still get the point across. Either this demo shows a
> > misunderstanding I have of gluUnProject or it shows a bug in the
> > function or opengl projections. Can someone check this over and see if
> > I'm just doing something wrong or if there's a bug that needs to be
> > filed?
>
> > The files are here:http://www.thenewsh.com/~newsham/unproj/
> > In particular:
>
> > unproj.java - full source to example
> > unproj-debug.apk - resulting apk file
> > unproj - directory with full ant-buildable project
> > unproj.zip - zip of directory
>
> > Tim
--
You received this message because you are subscribed to the Google
Groups "Android Developers" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/android-developers?hl=en
