Possible to use panda3d for plot data

General Discussion
1

I know that there are libraries specialized in python like matpliltib or vispy but can we do it with panda3D? can we create 2D/3D graphs?
my question is about the scale, how to represent in panda 1 unit?
1 unit is for example 1 mile/kilometer or 1L, 1M^3…

2

It’s probably fairly easily possible to create a plotting application in Panda3D either using a shader or by drawing lines using LineNodePath or LineSegs.

The common convention for units is that 1 panda unit corresponds to 1 metre, although theoretically you can make it anything you like.

3

thank you rdb

i see LineNodePathc and it’s very interesting, but seg not work for me
why my seg not draw ?

import sys
from direct.showbase.ShowBase import ShowBase
from pandac.PandaModules import *
from direct.directtools.DirectGeometry import LineNodePath

class Application(ShowBase):

    def __init__(self):
        ShowBase.__init__(self) 
        
        
        l = LineNodePath(render2d,'box',4,VBase4(1,0,0,1))
        p1 = (-.5,-.5,0)
        p2 = (-.5,.5,0)
        p3 = (.5,.5,0)
        p4 = (.5,-.5,0)
        l.drawLines([[p1,p2],[p2,p3],[p3,p4],[p4,p1]])
        l.create()
        
        ls = LineSegs()
        ls.setThickness(10)

        # X axis
        ls.setColor(1.0, 0.0, 0.0, 1.0)
        ls.moveTo(0.0, 0.0, 0.0)
        ls.drawTo(1.0, 0.0, 0.0)

        # Y axis
        ls.setColor(0.0, 1.0, 0.0, 1.0)
        ls.moveTo(0.0,0.0,0.0)
        ls.drawTo(0.0, 1.0, 0.0)

        # Z axis
        ls.setColor(0.0, 0.0, 1.0, 1.0)
        ls.moveTo(0.0,0.0,0.0)
        ls.drawTo(0.0, 0.0, 1.0)

        ls.create()
        
        segs = LineSegs( )
        segs.setThickness( 2.0 )
        segs.setColor( Vec4(1,1,0,1) )
        segs.create( )
        


Application().run()
4

For 2D graphs, you can have the library create an image that you upload to the GPU to use as a texture. This may also be possible with 3D graphs and 3D textures.

5

You need to actually place your LineSegs in the scene graph. The create() function returns a node:

node = ls.create()
render2d.attachNewNode(node)
1 Like
6

thank’s rdb it’s work !