I have recently been having clipping problems during rotation of the
objects when using OpenDX with hardware rendering to render isosurfaces.
These problems are similar to a post made to opendx-users in November
2002 (see below).
In addition I have also had picking problems whereby the area picked has
a value outside the area which is rendered.(This can easily be seen by
turning on the bounding box [Menu options->Rendering Options and set
Button Down to Box] and trying do do a pick or rotate operation. The
bounding box will jump/shift positions)
I have tracked these problems to compiling OpenDX with the -O3 compiler
option.
Under Linux compiling OpenDX 4.3 or OpenDX 4.2 with gcc 3.2.1 or gcc 3.3
with -O3 causes the problems (unwanted clipping when hardware rendering
is turned on and picking issues which exist in both hardware or software
rendering modes).
When compiling with -O2 there are no problems with either unwanted
clipping or picking errors.
The specific option that seems to be causing the problems is
-finline-functions (-O3 is essentially -O2 with -finline-functions and
-frename-registers)
Hi,
being completely new to OpenDX I ran into the following problem:
I import my data, reduce it, compute an isosurface, color it and render
it to an image.
Sometimes (not really reproducable, but frequently) when I rotate the
view parts of the isosurface disappear as if there was a clipping plane.
Does anybody know this behaviour? Is it a bug or a feature? How can I
circumvent it?
I have found out that this only occurs when hardware rendering is
activated. With Software rendering everything works fine. Quite a pity
since HW rendering is lots faster. Does anyone know a workaround for this?
--
"They that give up essential liberty to obtain a little temporary safety
deserve neither liberty nor safety."
~Benjamin Franklin
---------------------------------------------------
Raymond F Gasser
Graphics Programmer/Analyst
Scientific Computing and Visualization Group
Information Technology, Boston University
[EMAIL PROTECTED] (617)358-0545
http://scv.bu.edu/~rayg
