how to draw the line with setted width

[liusa80]

i try to draw the line with setted width,but i could look for the setting parameter.does anybody know how? thank u

[Escen]

Did you try material settings?

Code: Select all

  //set material   
  SMaterial mat;
   mat.Thickness = 5;
   mat.AntiAliasing=true
   mat.AmbientColor = mat.DiffuseColor = mat.EmissiveColor = irr::video::SColor(255,0,0,255);
   Driver->setMaterial(mat)
  //draw lines.....
  Driver->draw3DLine{......
   

Note that d3d does not support line thickness.

[liusa80]

thanks for your help.but it doesn't work

[liusa80]

anybody know how?

[greenya]

i try to draw the line with setted width,but i could look for the setting parameter.does anybody know how? thank u

With setted width ?
Not sure if i understand you, but:

#1

The line can be drawn using IVideoDriver::draw3DLine(...)
You need start point (vector3df -- 3 floats) and end point (the same as start).

So line in 3 dimensional space can be defined by 6 floats -- this is common definition and Irrlicht draw this data into line on the display with 1 call (draw3DLine() as i said above),

#2

BUT indeed, line can be defined also by:
- start point (vector3df)
- direction (vector 3df) // "start point" and "direction" already defines a ray
- width (1 float) // this will limit out ray to ending line.

If you need to draw line with #2nd type of data set, you need to make some vector calculations to get end point coordinates and draw the line in the same way as for #1.

[hybrid]

I think the question is regarding line thickness. Escen's solution is correct, and includes the mentioning of the d3d limitation. Nothing more to say, probably.

[Bate]

Just in case: You have to draw the line in your main loop between beginScene and endScene.

Code: Select all

driver->beginScene(true, true, SColor(0,0,0,0));

  SMaterial mat;
  mat.Thickness = 5;
  mat.AntiAliasing = true
  mat.EmissiveColor = irr::video::SColor(255,0,0,255);
  driver->setMaterial(mat)
  driver->draw3DLine(...);

driver->endScene();

[liusa80]

thank u,it works,but anothor question,when i set the value parameter"Thickness",it looks like cannot draw very big width,set 8.0f and 20.0f the effort like the same width.

[liusa80]

and set the width only works in opengl mode,really?

[hybrid]

Yes, only OpenGL and the sw renderers. And there's a maximum width that your gfx card supports, yes.

[kvakvs]

Modern video cards hardware can only draw simple Bresenham lines, no thick lines. Thick lines are simulated with 3D geometry (triangles and triangle strips).

So if you want full control over line rendering, with antialiasing, texturing, lighting, whatever you wish to control...

1. Build 2 points around your line start (half width left, and half width right), and then 2 points around your line end (again half width left, and half width right). Left and right are calculated using perpendicular vector to your line, there is easy algorithm on the internets, how to calculate a perpendicular.
2. Render the resulting quad with the color and quality settings you wish.
3. ????
4. Calculate profits.

[liusa80]

how to settle the problem ?

[liusa80]

i'll try kvakvs's method , wish to be settled

[hybrid]

This is a known limitation, there is a feature request/bug ticket filed, and this issue will be fixed in one of the next releases.