FXPHD – HOU236 – Pyrotechnic Explosions in Houdini

本课程由教授兼视觉特效艺术家 Liam Whitehouse 讲授，介绍如何使用 Houdini、Axiom 和 Solaris 中的 Karma XPU 创建详细的烟火爆炸效果。

多年来，创建详细的烟火爆炸一直是 Houdini 的主要优势之一，但 Axiom 旨在进一步改进这一点，让艺术家充分利用 GPU 来完成非常高细节的爆炸和烟雾模拟。这些模拟与其他 Houdini 系统配合使用，包括烟火爆发工具、烟火轨迹工具，当然还有使用 Solaris 设置镜头和使用 Karma XPU 快速渲染。本课程将涵盖所有这些方面以及更多内容，非常适合任何想要了解 Axiom 和 Houdini 中的烟火爆炸模拟的人。

第一节课：简介
我们查看示例场景设置并介绍 Houdini 的 Axiom GPU 稀疏流体求解器，研究如何使用它为 VFX 镜头创建详细的爆炸模拟。

第 2 类：火爆源
Pyro Burst Source 几何节点是一组出色的设置，用于在 Houdini 中获取爆炸类型模拟。我们来看看用于创建不同类型效果的所有设置。

第 3 课：Pyro Burst 到 Axiom
您将学习如何连接 Pyro Burst 设置以获取源，并将源转换为正确的命名，以便与 Axiom GPU 解算器配合使用，因为它使用的命名与 Houdini Pyro 模拟不同。这为使用 Axiom Solver 模拟爆炸奠定了基础。

第 4 课：公理概述
Axiom 解算器设置的概述，展示如何设置逼真的爆炸运动以实现动画噪音和烟雾和火焰干扰等效果。

第 5 课：照明
为了创建穿过透明烟雾的灯光，我们使用 Pyro Bake Volume 几何节点来创建一个详细且具有电影效果的爆炸，并通过体积进行光线散射。

第 6 课：添加烟雾
除了主爆炸之外，您还可以使用 Pyro Trails 和 Pyro Trail Path 几何节点模拟较小的烟雾轨迹，以复制爆炸中飞出的碎片和岩石，而不必手动设置带有发射的复杂粒子模拟。

第 7 课：Solaris 设置
一旦我们完成了爆炸模拟的第一遍，我们就可以在 Solaris 中构建一个节点网络，将所有几何体、着色器、灯光、相机和渲染设置整合在一起。

第 8 课：Karma XPU
创建 Pyro Bake Volume 设置后，我们现在可以将这些设置添加到 Karma XPU Pyro Shader，以便我们可以控制烟雾的透明度、光散射量以及用于渲染的火焰的温度和热度。

第 9 类：深色和浅色烟雾
电影镜头中的真实物理爆炸通常会有意设置为同时产生黑烟和淡烟以及橙色火焰，以尽可能地增加场景的视觉趣味和细节。

第 10 课：照明和渲染
一旦设置好材料，我们就可以设置灯光，为烟雾和爆炸渲染创建 3D 外观，使用 HDRI、远处的阳光和边缘光照亮镜头以供 vfx 审查。

Duration 5h 27m MP4

Title: FXPHD – HOU236 – Pyrotechnic Explosions in Houdini

Info:
This course, from professor and VFX artist Liam Whitehouse, covers how to create detailed pyrotechnic explosions using Houdini, Axiom, and Karma XPU in Solaris.

Creating detailed pyro explosions has been one of the key strengths of Houdini for many years but Axiom aims to improve that further by allowing artists to leverage the GPU entirely to complete very high detail explosions and smoke simulations. These simulations work with other Houdini systems including the pyro burst tool, pyro trails tool, and of course setup of the shots with Solaris and speedy rendering with Karma XPU. This course will cover all these aspects and more and is ideal for anyone wanting to learn about pyro explosion simulations in Axiom and Houdini.

Class 1: Introduction
We look at the example scene setup and cover an introduction to the Axiom GPU sparse fluid solver for Houdini, examaning how it can be used to create detailed explosion simulations for VFX shots.

Class 2: Pyro Burst Source
The Pyro Burst Source geometry node is an excellent group of settings for sourcing explosive type simulations in Houdini. We look at all the settings used to create different types of effects.

Class 3: Pyro Burst to Axiom
You will learn how to connect the Pyro Burst setup for sourcing and convert the source into the correct naming to work with the Axiom GPU solver, as it uses different naming than the Houdini Pyro simulations. This sets the stage for simulating the explosion using the Axiom Solver.

Class 4: Axiom Overview
An overview of the Axiom solver settings, showing how to setup realistic explosive movement to the effects including animated noise and disturbance of the smoke and fire.

Class 5: Lighting
To create lighting which transports through transparent smoke, we use the Pyro Bake Volume geometry node to create a detailed and cinematic looking explosion with light scattering through the volume.

Class 6: Adding Smoke
As well as a main explosion, you can also simulate smaller smoke trails to replicate debris and rocks flying off from the explosion using the Pyro Trails and Pyro Trail Path geometry nodes instead of having to manually set up complex particle simulations with emission.

Class 7: Solaris Setup
Once we have finished the first pass of our explosion simulation we can build a node network in Solaris to bring all our geometry, shaders, lights, camera and Render settings together.

Class 8: Karma XPU
After the creation of our Pyro Bake Volume settings, we can now add those settings to a Karma XPU Pyro Shader so that we can control the transparency of our smoke, the amount of light scattering, and the temperature and hotness of the fire we are using to render.

Class 9: Dark and light smoke
Real physical explosions in cinema shots are often intentionally setup to have both dark smoke and light smoke along with orange flames to give as much visual interest and detail in the scene as possible.

Class 10: Lighting and Rendering
Once our materials are set up, we can then setup our lights to create a 3D appearance for our smoke and explosion renders using HDRI, distant sunlight, and rim lights to light our shot for vfx review.