Re: [osg-users] [osgOcean] Wind speed representation
Hi, guys thanks for your quick answers! I checked in the header and indeed the speed is considered to be m/sec, it works fine for me I just want to make a connection between wind and sea state. Cheers, Dimitrios -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=19070#19070 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] [osgOcean] Wind speed representation
Hi, I was wondering if there is a connection of wind speed parameter of the ocean surface to real world wind speed. Is it representing m/sec or Km/h or it has some connection with ocean sea state? Thank you! Dimitrios -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=19010#19010 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] [3rdparty] osgOcean collision detection
Hi, you can certainly redistribute the boat model. Please be my guest!!! Thanks Dimitrios -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=18229#18229 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] [3rdparty] osgOcean collision detection
Hi, you 're right now I understand why I had some crashes from time to time Thanks! Cheers, Dimitrios -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=18014#18014 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] [3rdparty] osgOcean collision detection
Hi,
here's the code for normal interpolation I promised
osg::Vec3f OceanTile::normBiLinearInterp(float x, float y ) const{
float dx = x / _spacing;
float dy = y / _spacing;
unsigned int ix = dx;
unsigned int iy = dy;
dx -= ix;
dy -= iy;
osg::Vec3f s00 = getNormal(ix,iy);
osg::Vec3f s01 = getNormal(ix + 1,iy);
osg::Vec3f s10 = getNormal(ix,iy + 1);
osg::Vec3f s11 = getNormal(ix + 1,iy + 1);
return s00*(1.f - dx)*(1.f-dy) + s01*dx*(1.f-dy) + s10*(1.f - dx)*dy +
s11*dx*dy;
}
and the code for getSurfaceDataAt()
osg::Vec4f FFTOceanSurface::getSurfaceDataAt(float x, float y) {
if(_isDirty)
build();
const unsigned int SAMPLE_SIZE = 5;
//ocean surface coordinates
float oceanX, oceanY;
//value to return
osg::Vec4f surfData(0.0f,0.0f,0.0f,0.0f);
//df osg::Vec3f tileOffset;
//translate x, y to oceanSurface origin coordinates
oceanX = -_startPos.x() + x;
oceanY = _startPos.y() - y;
//calculate the corresponding tile on the ocean surface
unsigned int ix/*tile_x*/ = oceanX/_tileResolution;
unsigned int iy/*tile_y*/ = oceanY/_tileResolution ;
//This might not be corect but I don't want to ruin data encapsulation of
OceanDataType class
unsigned int frame = _oldFrame;
//Test if the tile is valid
if(ix _numTiles iy _numTiles){
const OceanTile data = _mipmapData[_oldFrame][0];//curData[
tile-getLevel() ];
float tile_x = oceanX - ix * _tileResolution;
float tile_y = oceanY - iy * _tileResolution;
osg::Vec3f norm = data.normBiLinearInterp(tile_x, tile_y);
surfData.x() = norm.x();
surfData.y() = norm.y();
surfData.z() = norm.z();
surfData.w() = data.biLinearInterp(tile_x, tile_y);
}
return surfData;
}
then you can position an object on the ocean surface by doing something like:
osg::Vec4f data(m_oceanSurface-getSurfaceDataAt (x,y));
then data.w() is the height and as rotation you can use something like:
(data.x()*180.0f/PI,data.y()*180.0f/PI,(1.0f - data.z())*180.0f/PI)
Cheers,
Dimitrios
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Re: [osg-users] [3rdparty] osgOcean collision detection
Hi all, the code that Jean Claude posted works like a sweet. I also wrote a function similar to biLinearInterp to interpolate the normals of 4 vertices. I renamed the function getHeightAt(x,y) to getSurfaceDataAt(x,y) that return an osg::Vec4f now. The x,y,z represent the interpolated normal and the w the surface height. Now when you apply rotation and translation (only the height) to an object you might except from seeing the object to follow the motion of the waves you can see it rotate a little bit, like it should be in real life. I will post the code soon. One other thing what is the functionality of _isDirty and buid() in Jean Claudes code ? It will save me a lot of time. Thanks! Cheers, Dimitrios -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=17992#17992 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] [3rdparty] osgOcean collision detection
Hi, I saw the Update function and understood that you're absolutely right! I saw more accurate results also! Yesterday I changed the function to retrieve the normal too. Now with the normal I can make the models not only to move up and down but rotate also when a wave passes. I will try to use biLinearInterp to interpolate the height between four vertices. For that function you must provide the indices (x,y) of three vertices? Is that correct? Thanks Cheers, Dimitrios -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=17735#17735 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] [3rdparty] osgOcean collision detection
Hi Kim, yesterday I realized that my object goes up and down from the water because: a) it is smaller than the distance of two vertices of the grid b) the vertice displacement that takes place to simulate the wave on larger objects it works fine! I used the linear interpolation function of OceanTile it seems to work ok but I am still testing. Thanks! Cheers, Dimitrios -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=17757#17757 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] [3rdparty] osgOcean collision detection
Hi, it seems to work fine but I am still testing. For big models of height 2.0 and more works fine, for smaller height models there are frames that goes above water, just a little though and also on some other frames just below the surface, especially on high wind speeds. This behavior might be correct but I 'll try to make it more realistic. For bigger models the behavior is OK. I am thinking of using the surface normal to calculate the models pitch and roll, but it will take sometime . Thanks! Cheers, Dimitrios -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=17697#17697 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] [3rdparty] osgOcean collision detection
Hi, I checked the _oldFrame and you are absolutely right. Thanks! Dimitrios -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=17686#17686 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] [3rdparty] osgOcean collision detection
Hi Kim Bale, your hints are valuable. As I've seen so far I need to know the height on a specific point on sea surface. I wrote a function in FFTOceanSurface passing the x,y of a point. That function finds the corresponding ocean tile and retrives the closest vertice using the getVertex of OceanTile function. That way I can program my objects on the sea surface to maintain that height from the sea zero level on every frame. I haven't done yet (actually it doesn't work so far) but I believe I am going to the right direction. I' ll make a post when I have good news. Thank you! Cheers, Dimitrios -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=17647#17647 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] osgOcean collision detection
Hi, is it possible to gain the information of a specific point (providing the x,y) on the ocean surface? Because I am using osgOcean on a project and I need to do some collision detection stuff. Thank you! Cheers, Dimitrios -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=17570#17570 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
