MeshDrawer doesn't rotate to the camera

C++ coding using Panda3D
1

So i tried to use MeshDrawer, i deduced from the manual
that MeshDrawer draws the particles with respect to
the camera, but in my case it doesn’t really happen.

here is my initial code:

PandaFramework framework;
framework.open_framework(argc, argv);
WindowFramework *window = framework.open_window();

MeshDrawer generator = MeshDrawer();
NodePath genNode = generator.get_root();

genNode.reparent_to(window->get_render());
generator.set_budget(1000);
genNode.set_depth_write(false);
genNode.set_transparency(TransparencyAttrib::M_alpha);
genNode.set_two_sided(true);
genNode.set_texture(TexturePool::load_texture(mydir+"/plate2.png"));
genNode.set_bin(“fixed”,0);
genNode.set_light_off(true);

and here is how i’m using it:

generator.begin(window->get_camera_group(),window->get_render());

		int numOfSegs = 5;
		LVector3f startPos(98,143,70),
				  endPos(379,471,80),
				  advancingVec=(endPos-startPos)/numOfSegs;

		for(int i=0; i<10; i++)
			generator.cross_segment(startPos,startPos + advancingVec * i,LVector4f((128./2048.)*14.,(128./2048.)*1.,256./2048.,128./2048.),3,LVector4f(1,1,1,0.7));
		
	generator.end();

Only for some positions of the camera i’m able to see
the draw (laser beam).

here is how i’m moving the camera:

NodePath cam = window->get_camera_group();
GraphicsWindow *gwin = window->get_graphics_window();

//Get cursor position 
if(gwin){
	cursorX = gwin->get_pointer(0).get_x(); 
	cursorY = gwin->get_pointer(0).get_y();

	float xsize = (float)window->get_graphics_window()->get_x_size(); 
	float ysize = (float)window->get_graphics_window()->get_y_size();

	if(cursorX < 10 )
		cam.set_x(cam,-4);
	if(cursorX > xsize - 10)
		cam.set_x(cam,4);
	if(cursorY < 10 )
		cam.set_z(cam,4);
	if(cursorY > ysize - 10)
		cam.set_z(cam,-4);
}

Thank you very much guys.

2

I ran into some thread with similar problem.
So i will try to add this:

particles.node().setBounds(BoundingSphere((0, 0, 0), 100))
particles.node().setFinal(True)

and see if it will fix the problem.

3

So it’s one man correspondence… :laughing:

But the last code i posted did help, and solve the problem.
So if any one have the same problem try to add these two lines of code…

4

Glad you found the solution, though it’s not clear to me how that particular solution solves the problem you described. Setting a bounding volume is necessary to prevent the particles from being culled (disappearing) from different points of view, but doesn’t have anything to do with rotating to the camera.

David