Line Of Sight Implementation

[adithyahk46]

Screen.Recording.2025-10-24.141515.mp4

for the below code the line of sight is working as above, but in that some modifications i have to make, i didn't get the reference for LOS
->goodline is turning to red when zoomin/zoomout happens,
->have to change the style of the line(width, dotted , dashed .etc)

auto* losNode = new osgEarth::Contrib::LinearLineOfSightNode(_mapNode, start, end);
losNode->setGoodColor(osg::Vec4(0,1,0,1));
losNode->setBadColor(osg::Vec4(1,0,0,1));
losNode->setDisplayMode(osgEarth::Contrib::LineOfSight::MODE_SPLIT);
losNode->setTerrainOnly(true);
_mapNode->addChild(losNode);

[gwaldron]

Hard to say but I will take a guess.

If one or both of your endpoints are on the ground or very close to the ground, small changes in terrain LOD can change the results.

You can probably change the line width or stippling using standard OSG state attributes? osg::LineWidth, osg::LineStipple

[adithyahk46]

is there any solution to stop that LOD terrain Changes

for Line Width i use below part , if change the width to higher value , it gives the render bin error , and no change in the line width,
instead use the osgEarth/LineString and FeatureNode in LinearLineOfSightNode::draw(bool backgroundThread) , from start point -> hitpoint and hit point to ->end Point so user can style line using osgEarth::Style for good and bad lines
{
float desiredWidth = 3.0f;
osg::LineWidth* lineWidth = new osg::LineWidth();
lineWidth->setWidth(desiredWidth);
geometry->getOrCreateStateSet()->setAttributeAndModes(lineWidth, osg::StateAttribute::ON);
}

[gwaldron]

Probably a good idea.
The LLOS node is very old and it would be nice to update it to use LineDrawable or FeatureNode.

You can limit the terrain from subdividing beyond a certain LOD with the terrain option

<map>
   <options>
      <terrain max_lod="10" ...

Or by calling

mapNode->getTerrainOptions().setMaxLOD