Re: [osg-users] Precipitation Effect, Snow, bad rendering at slow speed
Hi Massimo, Thanks for the pictures. Moving slow is a walking pace, not at 360km/h.. that's pretty fast in my book. The streaks are motion blurr on the particles as when you are moving fast the particle moves relative to the eye point between frames will be stretched out. As the particle is stretched out the alpha value also gets reduced so it becomes more transparent particle to make sure the overall coverage of the background is the same. So the slow case it looks like things are working correctly to me. For the fast case the motion blur support in PrecipitationEffect is failing as the camera is moving so fast between the particle cells that their is no previous frame position recorded for it to compute the motion blur for. This is a limitation/bug in PreciptationEffect. I wrote this class originally for a driving sim so it works well for driving speeds, but at jet aircraft speeds this particle cell issue rears it's head. These cells are virtual cells, which are in fact a single osg::Geometry that is transformed many times in the view in front of you, these virtual cells are reassigned on the fly to give you the effect of having an infinite particle system. I can think of two solutions - to better compute the previous frame position of a virtual cell that is newly coming into the view, or the more hacky solution, increase the depth of cells further out from camera so that the first frame that they become in view are miss out on the motion blur is far away enough from the camera as to not be seen. The former of the two solution really has to be the right way to go. Now fixing this bug will lead to motion blur at both your slow and fast speeds, which I can't say how you'll react to, as you picked out the slow viz as the one in error, rather than the fast speed. One could possible offer the option of removing the motion blur effect or scaling it down, but this itself might lead to other artifacts such as strobe like effect as you will find it easier to spot patterns in the particles as you go from cell to cell. Robert. On Mon, Dec 21, 2009 at 8:12 PM, Massimo Tarantini subbi...@yahoo.it wrote: From your description it sounds like an issue that occurs when the camera moves very fast relative to the particle system, rather than very slow. My only guess is that you've model units that aren't in meters so the velocities are out. Now i have also posted the 3 images to imageshack: http://img189.imageshack.us/img189/5565/static594.jpg http://img189.imageshack.us/img189/9955/movingslow526.jpg http://img189.imageshack.us/img189/5372/movingfast976.jpg Anyway, the problem is in movingslow526.jpg at 360kmh, while movingfast976.jpg at 1800kmh is better, and static594.jpg (stopped) is perfect. My terrain is generated with osgdem (non Geogentric), and is in UTM33/WGS84. The Geographics coordinates are in meters. Thanks.[/list] -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=21746#21746 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation Effect, Snow, bad rendering at slow speed
robertosfield wrote: Hi Massimo, Thanks for the pictures. Moving slow is a walking pace, not at 360km/h.. that's pretty fast in my book. The streaks are motion blurr on the particles as when you are moving fast the particle moves relative to the eye point between frames will be stretched out. [...] Thanks for the long answer, and sorry for my lack of precision about slow speed. ... -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=21806#21806 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation Effect, Snow, bad rendering at slow speed
From your description it sounds like an issue that occurs when the camera moves very fast relative to the particle system, rather than very slow. My only guess is that you've model units that aren't in meters so the velocities are out. Now i have also posted the 3 images to imageshack: http://img189.imageshack.us/img189/5565/static594.jpg http://img189.imageshack.us/img189/9955/movingslow526.jpg http://img189.imageshack.us/img189/5372/movingfast976.jpg Anyway, the problem is in movingslow526.jpg at 360kmh, while movingfast976.jpg at 1800kmh is better, and static594.jpg (stopped) is perfect. My terrain is generated with osgdem (non Geogentric), and is in UTM33/WGS84. The Geographics coordinates are in meters. Thanks.[/list] -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=21746#21746 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation Effect, Snow, bad rendering at slow speed
Hi Massimo, On Fri, Dec 18, 2009 at 6:04 PM, Massimo Tarantini subbi...@yahoo.it wrote: I have attached 3 Images to show what i mean. In the image moving_slow.jpg the camera is moving slowly towards the mountains, and the snow looks like rays of light coming out of the screen. The pictures didn't come through. I use the mailing lists, but checked the forum thread and it doesn't show any pictures either. From your description it sounds like an issue that occurs when the camera moves very fast relative to the particle system, rather than very slow. My only guess is that you've model units that aren't in meters so the velocities are out. Try the precipitation example to see if it works fine. With vync do you mean Wait Vertical Update ON/OFF? I have tried both in ATI Control Panel, and nothing change. vysnc is Vertical Sync (of the graphics swap buffers with monitor refresh), with will be likely Wait Vertex Update in your control panel. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] Precipitation Effect, Snow, bad rendering at slow speed
Hi all, i have added some snow to my scene (it's Christmas time!), after looking the example osgprecipitation. It renders very well when the scene is static, and quite well when moving fast, but very bad when moving slow. Code: osg::ref_ptrosgParticle::PrecipitationEffect precipitationEffect = new osgParticle::PrecipitationEffect; precipitationEffect-snow(1.0); /* It Does not work, if i set to false: what does it mean? */ precipitationEffect-setUseFarLineSegments(true); precipitationEffect-getFog()-setDensity(0.00012f); precipitationEffect-getFog()-setMode(osg::Fog::EXP2); precipitationEffect-getFog()-setFogCoordinateSource(osg::Fog::FRAGMENT_DEPTH); root-addChild( precipitationEffect.get() ); root-getOrCreateStateSet()-setAttributeAndModes(precipitationEffect-getFog()); Can you give me some hint? It Could a problem of my ATI Radeon 3650 AGP, or could be my code? Thanks -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=21661#21661 Attachments: http://forum.openscenegraph.org//files/moving_fast_976.jpg http://forum.openscenegraph.org//files/moving_slow_526.jpg http://forum.openscenegraph.org//files/static_594.jpg ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation Effect, Snow, bad rendering at slow speed
HI Massimo, What exactly do you mean by bad rendering? Do you have vync on? Robert. On Fri, Dec 18, 2009 at 1:58 PM, Massimo Tarantini subbi...@yahoo.it wrote: Hi all, i have added some snow to my scene (it's Christmas time!), after looking the example osgprecipitation. It renders very well when the scene is static, and quite well when moving fast, but very bad when moving slow. Code: osg::ref_ptrosgParticle::PrecipitationEffect precipitationEffect = new osgParticle::PrecipitationEffect; precipitationEffect-snow(1.0); /* It Does not work, if i set to false: what does it mean? */ precipitationEffect-setUseFarLineSegments(true); precipitationEffect-getFog()-setDensity(0.00012f); precipitationEffect-getFog()-setMode(osg::Fog::EXP2); precipitationEffect-getFog()-setFogCoordinateSource(osg::Fog::FRAGMENT_DEPTH); root-addChild( precipitationEffect.get() ); root-getOrCreateStateSet()-setAttributeAndModes(precipitationEffect-getFog()); Can you give me some hint? It Could a problem of my ATI Radeon 3650 AGP, or could be my code? Thanks -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=21661#21661 Attachments: http://forum.openscenegraph.org//files/moving_fast_976.jpg http://forum.openscenegraph.org//files/moving_slow_526.jpg http://forum.openscenegraph.org//files/static_594.jpg ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation Effect, Snow, bad rendering at slow speed
robertosfield wrote: HI Massimo, What exactly do you mean by bad rendering? Do you have vync on? Robert. Thanks for your answer Sir, and... sorry for my bad English. I have attached 3 Images to show what i mean. In the image moving_slow.jpg the camera is moving slowly towards the mountains, and the snow looks like rays of light coming out of the screen. With vync do you mean Wait Vertical Update ON/OFF? I have tried both in ATI Control Panel, and nothing change. ... -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=21678#21678 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation effect coming too fast, and hiding on some areas
Hi Fred and Jefferson,
On Thu, Dec 18, 2008 at 8:39 AM, fredlis...@free.fr wrote:
Unfortunately, it doesn't seem to work ( at least for me ). I modified the
osgprecipitation example to add a simple clip plane, and although the model
is clipped, the rain continues to appear in the half space clipped.
Attached the modified example.
I tested the modified example and it didn't function for a number of reasons..
First up the clipping plane has to be placed in eye coordinates and
osg::ClipNode didn't provide an option for placing it in an absolute
reference frame (an absolute/identity view matrix puts you in eye
coords) so I went ahead an added this to osg::ClipNode, so there now
is a ClipNode::setReferenceFrame(RefernceFrame) method along the same
lines as the same method in osg::LightSource, osg::TexGenNode and
osg::Camera (all instance have the same menaning.)
The next problem was that ClipNode was decorating the whole scene, not
just the precipitation effect so I restructed the example. So it now
looks like (note the setReferenceFrame and CliPlane in eye coords) :
osg::ref_ptrosg::Group group = new osg::Group;
if (clipDistance!=0.0)
{
osg::ref_ptrosg::ClipNode clipNode = new osg::ClipNode;
clipNode-addClipPlane( new osg::ClipPlane( 0 ) );
clipNode-getClipPlane(0)-setClipPlane( 0.0, 0.0, -1.0,
-clipDistance );
clipNode-setReferenceFrame(osg::ClipNode::ABSOLUTE_RF);
clipNode-addChild(precipitationEffect.get());
group-addChild(clipNode.get());
}
else
{
group-addChild(precipitationEffect.get());
}
group-addChild(loadedModel.get());
The osgprecitpitation example also now has a --clip distance command
line option to allow us to enable the above optional code path. Try
values like 10 or 20 when loading the standard test example lz.osg.
Once this was all in place the precipitation effect still wasn't being
clipped, so I investigated user defined clipping plane and GLSL and
found that we need to explicitly set the gl_ClipVertex variable the
vertex shader. Adding this fixed the clipping problem and hey presto
we can clip the precipitation effect and not the scene.
All these changes are now checked into svn/trunk and will be part of
the up coming 2.7.8 dev release.
Robert.
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Re: [osg-users] Precipitation effect coming too fast, and hiding on some areas
Hi Robert Jefferson,
- Jefferson Pinheiro a écrit :
2) Use an osg::ClipPlane to clip the precipitation effect. Using a
clip plan would also allow you to control angle of the clipping.
I don't know how to use that (I'm a beginner). Fred, I would be
grateful if you could share your code, if you do it.
Unfortunately, it doesn't seem to work ( at least for me ). I modified the
osgprecipitation example to add a simple clip plane, and although the model is
clipped, the rain continues to appear in the half space clipped.
Attached the modified example.
-Fred
/* OpenSceneGraph example, osgprecipitation.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the Software), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* THE SOFTWARE IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include osgDB/ReadFile
#include osgDB/FileUtils
#include osgUtil/Optimizer
#include osgUtil/CullVisitor
#include osgViewer/Viewer
#include osg/ClipNode
#include osg/MatrixTransform
#include osgUtil/TransformCallback
#include osgParticle/PrecipitationEffect
#include iostream
class MyGustCallback : public osg::NodeCallback
{
public:
MyGustCallback() {}
virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
{
osgParticle::PrecipitationEffect* pe =
dynamic_castosgParticle::PrecipitationEffect*(node);
float value = sin(nv-getFrameStamp()-getSimulationTime());
if (value-0.5)
{
pe-snow(1.0);
}
else
{
pe-rain(0.5);
}
traverse(node, nv);
}
};
int main( int argc, char **argv )
{
// use an ArgumentParser object to manage the program arguments.
osg::ArgumentParser arguments(argc,argv);
// set up the usage document, in case we need to print out how to use this
program.
arguments.getApplicationUsage()-setApplicationName(arguments.getApplicationName());
arguments.getApplicationUsage()-setDescription(arguments.getApplicationName()+
example provides an interactive viewer for visualising point clouds..);
arguments.getApplicationUsage()-setCommandLineUsage(arguments.getApplicationName()+
[options] filename ...);
arguments.getApplicationUsage()-addCommandLineOption(-h or
--help,Display this information);
arguments.getApplicationUsage()-addCommandLineOption(--snow
density,Set the snow with a density between 0 and 1.0);
arguments.getApplicationUsage()-addCommandLineOption(--rain
density,);
arguments.getApplicationUsage()-addCommandLineOption(--particleSize
size,);
arguments.getApplicationUsage()-addCommandLineOption(--particleColour
red green blue alpha,);
arguments.getApplicationUsage()-addCommandLineOption(--wind x y
z,Set the wind speed in model coordinates);
arguments.getApplicationUsage()-addCommandLineOption(--particleSpeed
float,Set the particle speed);
arguments.getApplicationUsage()-addCommandLineOption(--nearTransition
distance,Set the near transistion distance);
arguments.getApplicationUsage()-addCommandLineOption(--farTransition
distance,Set the far transistion distance);
arguments.getApplicationUsage()-addCommandLineOption(--particleDensity
density,Set the particle density);
arguments.getApplicationUsage()-addCommandLineOption(--cellSize x y
z,Set the cell size in model coordinates);
arguments.getApplicationUsage()-addCommandLineOption(--fogDensity
density,Set the fog density);
arguments.getApplicationUsage()-addCommandLineOption(--fogColour red
green blue alpha,Set fog colour.);
arguments.getApplicationUsage()-addCommandLineOption(-useFarLineSegments,Switch
on the use of line segments);
// construct the viewer.
osgViewer::Viewer viewer;
osg::ref_ptrosgParticle::PrecipitationEffect precipitationEffect = new
osgParticle::PrecipitationEffect;
float intensity;
while (arguments.read(--snow, intensity))
precipitationEffect-snow(intensity);
while (arguments.read(--rain, intensity))
precipitationEffect-rain(intensity);
float value;
while (arguments.read(--particleSize, value))
precipitationEffect-setParticleSize(value);
Re: [osg-users] Precipitation effect coming too fast, and hiding on some areas
Hi Robert, On Mon, Dec 15, 2008 at 7:55 AM, Robert Osfield robert.osfi...@gmail.comwrote: Hi Fred Jefferson, On Sun, Dec 14, 2008 at 10:49 AM, Frederic Bouvier fredlis...@free.fr wrote: I have a patch to PrecipitationEffect that seems to work. I'll submit it to osg-submissions I've just done a review of these changes and don't feel that there are mostr straightforward and effecient way to implement what is effectively near plan clipping. The code will make the vertex program slower, and not cut down on rasteristation and fill load. I feel a better route would be to either: 1) use two Camera's to depth partition the scene as suggested earlier in this thread, as this would give you control over the worlds depth range where the precipitation exists This one works! 2) Use an osg::ClipPlane to clip the precipitation effect. Using a clip plan would also allow you to control angle of the clipping. I don't know how to use that (I'm a beginner). Fred, I would be grateful if you could share your code, if you do it. Neither the above routes require any changes to the core OSG, and both would not affect the vertex program load, and would clip out fragment so would cut down the fragment program load so would be more efficient than the submitted fix. Could you test out the above suggestions? Thanks, Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org -- Jefferson Pinheiro (51) 9192 3535 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation effect coming too fast, and hiding on some areas
Hi Laurent, On Mon, Dec 15, 2008 at 10:18 AM, Laurent Di Cesare laurent.dices...@masagroup.net wrote: In my application, rain inside buildings is problematic if people enter the buildings (which they weren't supposed to do until recently). A clip plane method might work better than a near/far/depth partition. Using the stencil buffer for non planer clipping of fragments would work in the case of buildings. Or just switch the effect off but this would only be fine if you didn't look out of a window. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation effect coming too fast, and hiding on some areas
Hi Robert, - Robert Osfield a écrit : Hi Fred Jefferson, On Sun, Dec 14, 2008 at 10:49 AM, Frederic Bouvier fredlis...@free.fr wrote: I have a patch to PrecipitationEffect that seems to work. I'll submit it to osg-submissions I've just done a review of these changes and don't feel that there are mostr straightforward and effecient way to implement what is effectively near plan clipping. The code will make the vertex program slower, and not cut down on rasteristation and fill load. I feel a better route would be to either: 1) use two Camera's to depth partition the scene as suggested earlier in this thread, as this would give you control over the worlds depth range where the precipitation exists 2) Use an osg::ClipPlane to clip the precipitation effect. Using a clip plan would also allow you to control angle of the clipping. Neither the above routes require any changes to the core OSG, and both would not affect the vertex program load, and would clip out fragment so would cut down the fragment program load so would be more efficient than the submitted fix. Could you test out the above suggestions? I will test the osg::ClipPlane route. I don't feel confortable to take the depth partitioning route at this moment, and we already use this technique for other purpose in FlightGear, that may conflict with that. For the moment, the transition distance between the near camera and the far camera is too far away to be useful for this purpose. -Fred ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation effect coming too fast, and hiding on some areas
Robert Osfield wrote : Hi Fred Jefferson, On Sun, Dec 14, 2008 at 10:49 AM, Frederic Bouvier fredlis...@free.fr wrote: I have a patch to PrecipitationEffect that seems to work. I'll submit it to osg-submissions I've just done a review of these changes and don't feel that there are mostr straightforward and effecient way to implement what is effectively near plan clipping. The code will make the vertex program slower, and not cut down on rasteristation and fill load. I feel a better route would be to either: 1) use two Camera's to depth partition the scene as suggested earlier in this thread, as this would give you control over the worlds depth range where the precipitation exists 2) Use an osg::ClipPlane to clip the precipitation effect. Using a clip plan would also allow you to control angle of the clipping. In my application, rain inside buildings is problematic if people enter the buildings (which they weren't supposed to do until recently). A clip plane method might work better than a near/far/depth partition. However, even with such a solution, I'd still end up with rain visible in some buildings (depending on where the user places the camera). I'm sorry I'm not being very productive, because I have little to provide in terms of solutions, but I want to point out that a partial solution to the issue which slows down the shader, as Robert says, doesn't look like a good solution. Laurent. Neither the above routes require any changes to the core OSG, and both would not affect the vertex program load, and would clip out fragment so would cut down the fragment program load so would be more efficient than the submitted fix. Could you test out the above suggestions? Thanks, Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation effect coming too fast, and hiding on some areas
Hi Fred Jefferson, On Sun, Dec 14, 2008 at 10:49 AM, Frederic Bouvier fredlis...@free.fr wrote: I have a patch to PrecipitationEffect that seems to work. I'll submit it to osg-submissions I've just done a review of these changes and don't feel that there are mostr straightforward and effecient way to implement what is effectively near plan clipping. The code will make the vertex program slower, and not cut down on rasteristation and fill load. I feel a better route would be to either: 1) use two Camera's to depth partition the scene as suggested earlier in this thread, as this would give you control over the worlds depth range where the precipitation exists 2) Use an osg::ClipPlane to clip the precipitation effect. Using a clip plan would also allow you to control angle of the clipping. Neither the above routes require any changes to the core OSG, and both would not affect the vertex program load, and would clip out fragment so would cut down the fragment program load so would be more efficient than the submitted fix. Could you test out the above suggestions? Thanks, Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation effect coming too fast, and hiding on some areas
Hi Fred, On Sat, 13 Dec 2008 17:02:38 +0100, Frederic Bouvier fredlis...@free.fr wrote: If you want to see this funny effect in action, watch this video http://www.vimeo.com/2511328 ( move forward to 5:00 ) Very nice vid. But besides from raining inside the plane, it seems that the rain particles are too vertical - like the particles have a transform that follows the camera. Hmm.. I don't know, but you would expect horizontal rain at high speeds. I managed to get horizontal rain with the osg's precepitation effect. But maybe vertical rain is your intent? -- Joakim Simonsson ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation effect coming too fast, and hiding on some areas
HI Joakim Fred, I noticed the same vertical rain artifact. osgParticle::PreciptiationEffect will normally fall vertically but when the camera moves it will appear with the correct motion, so it looks like the effect is moving with the camera with this usage, normally the effect would be move with the world, not the camera. Robert. On Sun, Dec 14, 2008 at 9:47 AM, Joakim Simonsson joa...@autosim.no wrote: Hi Fred, On Sat, 13 Dec 2008 17:02:38 +0100, Frederic Bouvier fredlis...@free.fr wrote: If you want to see this funny effect in action, watch this video http://www.vimeo.com/2511328 ( move forward to 5:00 ) Very nice vid. But besides from raining inside the plane, it seems that the rain particles are too vertical - like the particles have a transform that follows the camera. Hmm.. I don't know, but you would expect horizontal rain at high speeds. I managed to get horizontal rain with the osg's precepitation effect. But maybe vertical rain is your intent? -- Joakim Simonsson ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation effect coming too fast, and hiding on some areas
Hi Robert, Robert Osfield a écrit : Hi Fred, On Sat, Dec 13, 2008 at 4:02 PM, Frederic Bouvier fredlis...@free.fr wrote: The same problem affect FlightGear too : it rains into the cockpit. Would it be possible to kill a particle when it comes under a certain distance from the viewer ? If you want to see this funny effect in action, watch this video http://www.vimeo.com/2511328 ( move forward to 5:00 ) The particle positions are generated down in the vertex program, so to cull based on position them you'd need to add logic into the vertex program to modify the alpha value to 0.0 to make it disappear. It's worth mentioning you can't cull vertices and associated primitives with a vertex program as it's strictly one vertex one vertex out. You could use a geometry shader to cull, or a fragment shader. Thank you for pointing out the direction to take. A simpler route would be to use the stencil buffer to clip out the fragment where you don't want rain. I don't think it will work because we want to see rain through the windshield but we don't want to see droplets or snowflakes in front of it. Another route would be to drawn the scene in two passes, first draw the terrain and precipitation effect, then draw the cockpit. Using such an approach would allow you to depth partition the scene and get better depth precision for the two parts of the scene. Personally this would be the route I'd take. Same problem here. Snowflakes in front of the windshield will not be erased. I have a patch to PrecipitationEffect that seems to work. I'll submit it to osg-submissions -Fred -- Frédéric Bouvier http://my.fotolia.com/frfoto/ Photo gallery http://fgsd.sourceforge.net/FlightGear Scenery Designer ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation effect coming too fast, and hiding on some areas
Jumping into the thread, Robert Osfield a écrit : Second question It also rains inside my car. I tried adding a node mask for that, but it didn't seem to work. Is it possible not to make it rain inside the cars (which are on a separete osg::Group)? PrecipitationEffect doesn't have an support itself for constraining the effect to appear inside/outside specified geometries. The best thing you could do would be to either try using the stencil buffer to prevent the fragments of the effect being rendered where you don't want them. The same problem affect FlightGear too : it rains into the cockpit. Would it be possible to kill a particle when it comes under a certain distance from the viewer ? If you want to see this funny effect in action, watch this video http://www.vimeo.com/2511328 ( move forward to 5:00 ) -Fred -- Frédéric Bouvier http://my.fotolia.com/frfoto/ Photo gallery http://fgsd.sourceforge.net/FlightGear Scenery Designer ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation effect coming too fast, and hiding on some areas
I think there is a big hole somewhere on the cocpit's ceiling :P 2008/12/13 Frederic Bouvier fredlis...@free.fr Jumping into the thread, Robert Osfield a écrit : Second question It also rains inside my car. I tried adding a node mask for that, but it didn't seem to work. Is it possible not to make it rain inside the cars (which are on a separete osg::Group)? PrecipitationEffect doesn't have an support itself for constraining the effect to appear inside/outside specified geometries. The best thing you could do would be to either try using the stencil buffer to prevent the fragments of the effect being rendered where you don't want them. The same problem affect FlightGear too : it rains into the cockpit. Would it be possible to kill a particle when it comes under a certain distance from the viewer ? If you want to see this funny effect in action, watch this video http://www.vimeo.com/2511328 ( move forward to 5:00 ) -Fred -- Frédéric Bouvier http://my.fotolia.com/frfoto/ Photo gallery http://fgsd.sourceforge.net/FlightGear Scenery Designer ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org -- Ümit Uzun ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation effect coming too fast, and hiding on some areas
Hi Fred, On Sat, Dec 13, 2008 at 4:02 PM, Frederic Bouvier fredlis...@free.fr wrote: The same problem affect FlightGear too : it rains into the cockpit. Would it be possible to kill a particle when it comes under a certain distance from the viewer ? If you want to see this funny effect in action, watch this video http://www.vimeo.com/2511328 ( move forward to 5:00 ) The particle positions are generated down in the vertex program, so to cull based on position them you'd need to add logic into the vertex program to modify the alpha value to 0.0 to make it disappear. It's worth mentioning you can't cull vertices and associated primitives with a vertex program as it's strictly one vertex one vertex out. You could use a geometry shader to cull, or a fragment shader. A simpler route would be to use the stencil buffer to clip out the fragment where you don't want rain. Another route would be to drawn the scene in two passes, first draw the terrain and precipitation effect, then draw the cockpit. Using such an approach would allow you to depth partition the scene and get better depth precision for the two parts of the scene. Personally this would be the route I'd take. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] Precipitation effect coming too fast, and hiding on some areas
I'm working on a driving project on OSG, and now I am making it rain. I added a precipitation effect for that. My scale is 1 unit = 1 cm. *First question:* When my car runs just a bit (say, 5 km/h), the rain comes at my face as though I was running at 200 km/h. And if I run faster than 20 km/h or so, the rain bacomes glitchy (looks like it's snowing, too). How do I change the speed at which the rain comes? *Second question* It also rains inside my car. I tried adding a node mask for that, but it didn't seem to work. Is it possible not to make it rain inside the cars (which are on a separete osg::Group)? Thanks, -- Jefferson Pinheiro ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation effect coming too fast, and hiding on some areas
Hi Robert, On Fri, Dec 12, 2008 at 2:26 PM, Robert Osfield robert.osfi...@gmail.comwrote: Hi Jefferson, On Fri, Dec 12, 2008 at 3:56 PM, Jefferson Pinheiro jeffersonmpinhe...@gmail.com wrote: I'm working on a driving project on OSG, and now I am making it rain. I added a precipitation effect for that. My scale is 1 unit = 1 cm. First question: When my car runs just a bit (say, 5 km/h), the rain comes at my face as though I was running at 200 km/h. And if I run faster than 20 km/h or so, the rain bacomes glitchy (looks like it's snowing, too). Shudder. Why or why would you have such a scale? Can't you just have a sensible scale like 1 unit = 1m? Even so, my colleague's project is on that scale and the same thing happens. I you really must have such as scale then try putting a scale above the PrecipitationEffect. setParticleSize? I tried increasing that, and big values causes the rain to look like snow; lower values makes it look normal or too small. Or adding a matrix transform and scale matrix? That didn't seem to work, either. How do I change the speed at which the rain comes? Have you looked at the API? I tried several combinations of setParticleSpeed, wind and cell size, the problem persisting. Is it possible to just disable the effect of rain coming at your face when the camera moves forward? Second question It also rains inside my car. I tried adding a node mask for that, but it didn't seem to work. Is it possible not to make it rain inside the cars (which are on a separete osg::Group)? PrecipitationEffect doesn't have an support itself for constraining the effect to appear inside/outside specified geometries. The best thing you could do would be to either try using the stencil buffer to prevent the fragments of the effect being rendered where you don't want them. Thanks, I'll take a look at that. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org -- Jefferson Pinheiro ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation Effect
Hi Robert, Thank you for quick response. I have three PrecipitationEffect active at one time. I am trying for snow, rain, hail effect active at one time. Selman On Wed, Sep 10, 2008 at 3:35 PM, Robert Osfield [EMAIL PROTECTED]wrote: Hi Selman, On Wed, Sep 10, 2008 at 1:13 PM, selman duatepe [EMAIL PROTECTED] wrote: I have multiple precipitation effect objects. When I set the wind parameters of precipitation effect objects, only one precipitation effect object influence this wind parameters, the others are not. Anyone experienced about this problem? I haven't personally tried multiple osgParticle::PrecipitationEffect, when I wrote it I had in mind that only one would likely be active at any one time. Do you have multiple PrecipitationEffect active at one time? What effect are you trying for? If you have multiple effects on at one time then perhaps lazy state updating on the uniform might be causing problems. This is just a wild guess though. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Precipitation Effect
Hi Selman, On Wed, Sep 10, 2008 at 1:13 PM, selman duatepe [EMAIL PROTECTED] wrote: I have multiple precipitation effect objects. When I set the wind parameters of precipitation effect objects, only one precipitation effect object influence this wind parameters, the others are not. Anyone experienced about this problem? I haven't personally tried multiple osgParticle::PrecipitationEffect, when I wrote it I had in mind that only one would likely be active at any one time. Do you have multiple PrecipitationEffect active at one time? What effect are you trying for? If you have multiple effects on at one time then perhaps lazy state updating on the uniform might be causing problems. This is just a wild guess though. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
