• Houdini Python开发实战 课程笔记


    P2 + P3 + P4 + P5 - 基础:

    1. Houdini中使用Python的地方

    2. Textport:可使用cd、ls等路径操作的命令(命令前加%,可在python中使用)

    3. Source Editor

    在Source Editor中定义函数

    在其他地方调用

    hou.session.getChildren(hou.node("/"))

    4. Python Shell 

    示例

    p2

    obj = hou.node("/obj")
    obj.createNode("geo")
    
    hou.cd("/obj/geo")
    
    # 返回当前路径
    hou.pwd()
    
    file1 = hou.node("./file1")
    file1.destory()
    
    
    hou.pwd().createNode("shpere")
    shpere = hou.node("shpere1")
    hou.pwd().createNode("box1")
    box = hou.node("box")
    hou.pwd().createNode("merge")
    merge = hou.node("merge1")
    
    # 将box和shpere联合起来
    merge.setFirstInput(sphere, 0)
    merge.setNextInput(box)

    p3

    # 返回merge联合的节点
    merge.inputs()
    
    # 将merge联合的box去除
    merge.setInput(1,None)
    
    # 返回父节点及子节点
    merge.parent()
    obj.children()
    
    # 返回子节点元组的函数
    def getChildren(node):
        childList = []
        for n in node.children():
             childList.append(n)
        return childList
    # 调用函数
    getChildren("/obj/geo1")
    getChildren("/")
    
    # 返回场景中所有节点的元组的函数
    def getChildren(node):
        childList = []
        for n in node.children():
             childList.append(n)
             if n.children():
                 childList += getChildren(n)
        return childList
     

    p4

    # 操作节点的参数
    
    # 获得参数
    parm = hou.parm("./shpere1/radx")
    # 取参数值
    parm.eval()
    # 修改值
    parm.set(5.0)
    
    parmtuple = hou.parmTuple("./shpere1/rad")
    parmtuple.eval()
    parmtuple.set((5.0, 5.0, 5.0))

     p5 

    可通过将界面元素(节点、参数、工具)拖进Python Shell获得其代码定义

    # 取得节点的name
    hou.pwd().name()
    
    # 取得帮助
    help(hou.pwd())

    Python文档:Houdini - Help

      

    # 将多个节点布局好
    hou.pwd().layoutChildren()
    
    sphere.setParms({"radx": 3.0 , "tx": 2.0})

    P6 - 创建工具栏工具: 

    1.  New Shelf

      Name - 小写 加 下划线

      Label - 首字母大写

    2. New Tool

      

      Options中指定Name和Label

      Script中写代码

    # 点击工具得到对话框
    hou.ui.displayMessage("Hello Houdini !")
    
    
    # box_tool 创建一个box节点
    geoNet = hou.ui.paneTabOfType(hou.paneTabType.NetworkEditor)
    
    position = geoNet.selectPosition()
    
    box = geoNet.pwd().createNode("box")
    
    box.setPosition(position)

    P7 + P8 - 创建螺旋线工具:

    1. 工具栏 kwargs参数(世界列表)

      包含:按键信息、pane信息、View信息

    2. 自定义工具-螺旋线

    from math import sin, cos
    
    geoNet = hou.ui.paneTabOfType(hou.paneTabType.NetworkEditor)
    
    spiral = geoNet.pwd().createNode("curve")
    
    coordsParm = spiral.parm("coords")
    
    inputParms = readMultiInput(message = "Enter parameters:" , input_labels = ["height", "lRadius", "uRadius", "frequency"], initial_contents = ["20", "10", "5", "3"])
    
    height = float(inputParms[1][0])
    lRadius = float(inputParms[1][1])
    uRadius = float(inputParms[1][2])
    frequency = float(inputParms[1][3])
    
    coordsStr = ""
    
    radius = lRadius
    step = (lRadius - uRadius) / (height * frequency)
    
    for i in range(int(height * frequency)):
        px = str(radius * sin(i))
        py = str(i / frequency)
        pz = str(radius * cos(i))
        
        coordsStr += px + ", " + py + ", " + pz + " " 
    
        radius -= step
    
    coordsParm.set(coordsStr)

    P9 - P15 -  创建sop节点:

    创建 “Add Color SOP” 节点

    1. New Operator Type 

    2. 代码

    import hou
    import random
    
    node = hou.pwd()
    geo = node.geometry()
    
    # 给定种子 保证每次运行otl得到的结果相同
    random.seed(123)
    
    colorAttrib = geo.addAttrib(hou.attribTypr.Point, "Cd", (1.0, 1.0, 1.0))
    
    color = hou.Color()
    
    pointsNum = len(geo.points())
    
    for point in geo.points():
        pos = point.position()
    
        px = pos[0]
        py = pos[1] + random.random() * random.choice([-1,1])
        pz = pos[2]
        
        point.setPosition((px, py, pz))
    
        value = float(point.number()) / pointsNum
        color.setHSV((value * 255, 1.0, 1.0))
        point.setAttribValue(colorAttrib, color.rgb())
    

    创建 “Color Falloff SOP” 节点

    1. 添加节点,并为节点添加两个参数

    2. Color Falloff 效果 - 代码

    import hou
    import random
    
    node = hou.pwd()
    geo = node.geometry()
    
    # 给定种子 保证每次运行otl得到的结果相同
    random.seed(123)
    
    colorAttrib = geo.addAttrib(hou.attribTypr.Point, "Cd", (1.0, 1.0, 1.0))
    
    color = hou.Color()
    
    position = hou.Vector3(node.parmTuple("position").eval())
    falloff = max( node.parm("falloff").eval(), 0.0001)
    
    for point in geo.points():
        pos = point.position()
    
        px = pos[0]
        py = pos[1] # + random.random() * random.choice([-1,1])
        pz = pos[2]
        
        point.setPosition((px, py, pz))
    
        distance = (pos - position)
    
        value = min(distance / falloff , 1.0)
        color.setHSV((value * 255, 1.0, 1.0))
        point.setAttribValue(colorAttrib, color.rgb())

    3. Color Wave 效果 - 代码

    import hou
    import random
    
    node = hou.pwd()
    geo = node.geometry()
    
    # 给定种子 保证每次运行otl得到的结果相同
    random.seed(123)
    
    colorAttrib = geo.addAttrib(hou.attribTypr.Point, "Cd", (1.0, 1.0, 1.0))
    
    color = hou.Color()
    
    position = hou.Vector3(node.parmTuple("position").eval())
    falloff = max( node.parm("falloff").eval(), 0.0001)
    frequency = max( node.parm("frequency").eval(), 0.0001)
    height =  node.parm("height").eval()
    
    for point in geo.points():
        pos = point.position()
    
        distance = (pos - position)
    
        value = abs(sin( min(distance / falloff , 1.0) ) * frequency)
        color.setHSV((value * 255, 1.0, 1.0))
        point.setAttribValue(colorAttrib, color.rgb())
    
        px = pos[0]
        py = pos[1]  + height * color.rgb()[1]
        pz = pos[2]
        
        point.setPosition((px, py, pz))

    P13 动画

    4. Color Falloff基础上  添加 法线  - 代码

    #primitive type : mesh || NURBS
    
    import hou
    import random
    
    node = hou.pwd()
    geo = node.geometry()
    
    # 给定种子 保证每次运行otl得到的结果相同
    random.seed(123)
    
    colorAttrib = geo.addAttrib(hou.attribTypr.Point, "Cd", (1.0, 1.0, 1.0))
    
    color = hou.Color()
    
    position = hou.Vector3(node.parmTuple("position").eval())
    falloff = max( node.parm("falloff").eval(), 0.0001)
    u_div = hou.evalParm("u_div")
    v_div = hou.evalParm("v_div")
    threshHold = hou.evalParm("threshHold")
    height = hou.evalParm("height")
    
    surface = geo.iterPrims()[0]
    
    for point in geo.iterPoints():
        pos = point.position()
    
        px = pos[0]
        py = pos[1]
        pz = pos[2]
        
        point.setPosition((px, py, pz))
    
        distance = (pos - position)
    
        value = min(distance / falloff , 1.0)
        color.setHSV((value * 255, 1.0, 1.0))
        point.setAttribValue(colorAttrib, color.rgb())
    
    for uNum in xrange(u_div + 1):
        u = float(uNum) / u_div
        for vNum in xrange(v_div + 1):
            v = float(vNum) / v_div
            uvColor = surface.attribValueAt("Cd", u, v)
            pos0 = surface.positionAt(u, v)
    
            pos1 = pos0 + surface.normalAt(u, v) * height
    
            ploy = geo.createPolygon()
            poly.setIsClosed(false)
    
            if uvColor[2] > threshHold:    # 只给绿色的地方添加法线(0.9)
    
                for p in [pos0, pos10:
                    point = geo.createPoint()
                    point.setPosition(p)
                    point.setAttribValue(colorAttrib, uvColor)
                    poly.addVertex(point)

    5. 将4完成的sop连接到 Add Color sop下

    部分变量重复

    修改4的代码为

    #primitive type : mesh || NURBS
    
    import hou
    import random
    
    node = hou.pwd()
    geo = node.geometry()
    
    # 给定种子 保证每次运行otl得到的结果相同
    random.seed(123)
    
    colorAttrib = geo.findPointAttrib("Cd")
    
    
    position = hou.Vector3(node.parmTuple("position").eval())
    falloff = max( node.parm("falloff").eval(), 0.0001)
    u_div = hou.evalParm("u_div")
    v_div = hou.evalParm("v_div")
    threshHold = hou.evalParm("threshHold")
    height = hou.evalParm("height")
    
    surface = geo.iterPrims()[0]
    
    
    
    for uNum in xrange(u_div + 1):
        u = float(uNum) / u_div
        for vNum in xrange(v_div + 1):
            v = float(vNum) / v_div
            uvColor = surface.attribValueAt("Cd", u, v)
            pos0 = surface.positionAt(u, v)
    
            pos1 = pos0 + surface.normalAt(u, v) * height
    
            ploy = geo.createPolygon()
            poly.setIsClosed(false)
    
            if uvColor[2] > threshHold:    # 只给绿色的地方添加法线(0.9)
    
                for p in [pos0, pos10:
                    point = geo.createPoint()
                    point.setPosition(p)
                    point.setAttribValue(colorAttrib, uvColor)
                    poly.addVertex(point)

    再增加一个sop 来控制法线的粗细(width)

    PS:

      查看渲染过程中的点的信息  Details View(P12 19min)

      可在Parameters中限制参数的取值范围 (P11 3min)

     P16 - P19 -  表达式:

    教程地址:https://www.bilibili.com/video/av33143116/?p=1

    PS:程序员看这个教程代码的讲解过程,真的要急死。。。

  • 相关阅读:
    Panel内嵌入子窗体
    Dictionary绑定到ComboBox显示值,实际值
    WinFrom 窗体内嵌子窗体
    Task基础创建Task,Task传参,获取Task返回值
    Task的休眠
    ThreadLocal 弱引用和内存泄漏
    ThreadLocal核心方法源码分析
    ThreadLocal实现原理、内部结构
    ThreadLocalMap源码分析
    ribbon & feign个性化配置
  • 原文地址:https://www.cnblogs.com/farewell-farewell/p/11608056.html
Copyright © 2020-2023  润新知