HOUDINI 火焰特效 Pyro FX

03-06

火焰模擬 Pyro Simulation

創建一個火焰模擬 Create a Flame Simulation:

創建一個球體幾何節點 Create a Sphere Geo Node >
在選定節點時 On Node Selected >
火焰特效菜單欄 Pyro FX Menu Bar >
選擇一個模擬預設 Pick a Simulation Preset (此次為火焰 Flame in this case) >
點擊它 Click On it >

請注意，HOUDINI會自動為火焰模擬生成一個節點區塊 Notice that HOUDINI automatically generates a block of nodes for Flame simulation.

渲染模擬 Render the Simulation:

在/mat網路（VEX 生成器）中 In the /mat Network (VEX Builder) >
在選定火焰節點時 On Flame Node Selected >
導航到渲染視圖 Navigate to the Render View >
按下渲染 Press Render >

探索流體源節點 Exploring the Fluid Source Node:

回到/ obj網路中 Dive Back to the /obj Network >
右鍵點擊create_fuel_volume節點 Right Mouse Click On Node create_fuel_volume >
顯示節點信息... Show Node Information… >

請注意，它會創建兩個參數 Notice that it creates TWO Parameters - - 燃料和溫度 Fuel & Temperature.

對於基本的火焰模擬 For a basic Pyro Simulation,

想要產生任何效果都必須具備這兩個體積 These Two volumes present are ALWAYS needed for the simulation to have any effect.

簡而言之，燃料是火焰可以誕生的區域 In a nutshell, the fuel is the area where pyro can birth from,

溫度是指燃料點燃並變為火焰的體積 temperature is a volume that tells that fuel to ignite and turn into fire.

[TAB] 標量 Scalar Volumes >
方法 Method [ ] 源的生成 Building of the source >
從幾何構建SDF Build SDF From Geometry

注釋Side Note:

SDF決定給定點 x與Ω邊界的距離（表面）網友Sebkaine對此有一個很好的解釋，以幫助理解SDF：SDF determines the distance of a given poting x from the boundary of Ω (surface) A Nice explaination from Sebkaine to help understanding SDF :

場 =存儲數據的3D網格 Field = a 3D grid where you store data

距離=在此網格中，您存儲標量（浮點）值，該值包含您在網格中評估的點P與位於對象表面上的最近點之間的距離Cp Distance = in this grid you store a scalar (float) value that contain the distance between the point P you evaluate in the grid and the closest point located on the surface of the object Cp

標記 =因為如果該點在對象之外，則該值可以是正值，或者如果該點在對象內，則該值可以是負值 Sign = because this value can be either positive if the point is outside the object or negative if the point is inside the object

[TAB] 速度體積 Velocity Volumes >
添加速度 Add Velocity > (這會創建速度參數 This creates a velocity parameter)
[TAB] 捲曲噪音 Curl Noise >
添加捲曲雜訊 Add Curl Noise > (火焰的初始速度不會朝任意方向前進，但會根據速度場被強制排出 The initial velocity of the fire will not be heading in a arbitrary direction, but will be forced out based on the velocity field.)
[TAB] 容器設置 Container Setting >
初始化 Initialize [ ] >
來源燃料 Source Fuel > (用於火焰模擬 for Fyro sim)

火焰模擬概述 Overview of the Pyro Simulation:

進入到/ obj / pyro_sim網路 Dive into the /obj/pyro_sim Network >
在來源體積節點 On Node Source Volume > 在這裡進行體積操作 Where you can do Volume Operation
選中火焰解算器時 On Node pyrosolver >
[TAB] 燃燒 Combustion > 在這裡進一步控制燃料和溫度的相互作用 Where you have further control of your fuel and temperature interaction.
啟用燃燒 Enable Combustion > 在進行火焰模擬時，一定要確保它處於開啟狀態 Always make sure this is ON when you do a fire simulation
選中調整容器節點時 On Node resize_container > 在這裡更改邊界框的大小。一定要始終盒子的優化 Where you can change the size of the Bounding Box. Be sure to always optimize your box.
邊界框 Bounding box
選中火焰節點（煙霧對象）On Node pyro (Smoke Object) >
分區大小 Division Size [ ] > 值越高，模擬速度越快，解析度越低 / 反之亦然 Higher the value, faster to simulate, lower the resolution. / Vise versa.

在這裡整理和記錄Pluralsight網站課程筆記

Introduction to Houdini Pyro FX by Sam Rickles

不署版權，歡迎轉載。