cmiVFX: Houdini L-System Essentials
English | Team: N/A | .MP4 | 1.8 GB
Genre: Video Training
English | Team: N/A | .MP4 | 1.8 GB
Genre: Video Training
Upon general request,this is the first video ever released about this immense and yet not well-known field of computer graphics. L-systems are a very useful language for describing fractal looking objects and branching structures. It's mainly used in environmental design, both artistic and scientific, to create realistic plants and trees and to simulate complex botanical animated phenomena. It has been used in special effects in a great variety of films to create anatomical patterns such as neurons in Fight Club or vessels in Hollow-Man 2.In these videos, we want to unleash the power of the l-systems by showing you the maximum of different things you can make with them:From the large topic of plant and tree modeling to tentacle animation, wire DOPs, lightning effects, complex crack generation, snowflakes, corals, L-system based surfaces, city pattern creation, blood flow through bronchus, making L-systems more scriptable and much more ( generalized recursive modeling). For plants, instead of showing you in full detail how to model an orchid and let you find your way alone to model a tulip or liliac we took another smooth but yet very in-depth and comprehensive approach where you will learn ALL the techniques and acquire methodology to model ANY plant or tree through complete key examples.
Mastering The L-Systems Language
F,f, ; - &,^; ! .... What do you mean? Learn all the L-system commands, not as a painful list to remember like your irregular verbs, but learn how they're most commonly used. Learn the difference between node rewriting and edge-rewriting. Learn about parametric l-systems, stochastic l-systems, learn how to use global variables, placeholders, conditional statements, expressions.
Pen and Paper / Application
Unlike in some other fields, L-system creation and plant modeling often require than you take you time to represent your vegetable to find its formula using a pen and a paper. We also help the user to find its way and to explain L-systems concepts with a large number of schematics on the whiteboard. As if you were in classroom with a real teacher.
L-system without some elementary notions of botany is like knowing some words without speaking the language. We introduce you to simple yet very realistic models of tree ( both coniferous and deciduous), using variables to interactively change the size of the branches, their thickness, the different angles, adding gravity etc. We show you how t o work separately with the leaves to have more control over their size and orientation.
General Plant Model
Botany is an immense field! Up to several millions of different species on earth, not to mention all the imaginary plants you may want to design!! Even restricting ourselves to the main categories, and the more common plant, we need to reduce diversity and to organize morphological description of plants. We give you some methodology to organize your plant description ( whether static or animated ) and help you find its L-system formula, starting with a general depiction of all the botanical events, then adding some timing.
Growth And Development
We introduce you to simple growth models for plant animation, ( for example basitonic, with lower branches growing longer than upper branches and acrotonic, where it is the opposite). We show you how to control growth with parameters and counters, and how to have multiple growth phases and flowering sequences with simple formulas.
Modeling Polygons in L-Systems
Even if L-systems are primarily designed for branches and branching structures, they can also be used for polygon modeling build upon a branched structure.We teach you how to model plant leaves with l-systems in a way which takes advantage of l-system recursively to create complex-looking growing organs such as dentate slightly bent rose leaves.
L-Systems as Control Structures
Another use of l-system between polygon modeling and branch modeling is to use l-systems to create the control structure of a Nurbs Surface, allowing complex and yet very precise animation of this nurbs through the use of simple commands and parameters in l-systems.This is perfectly suitable for petal opening. And here we take you to a more complex example of a multi-lobed banana-tree leaf, where we also use an L-system in conjunction with COPS to create the contour of the plant with a trimming curve.
Phyllotaxis - THE ROSE
Phyllotaxis is a botanical term which describes the organization of plant organs like petals, pinecones... in regular spiral for minimal space occupation. We teach you how to create a gorgeous rose flower with multiple petals, animated with l-systems control structures, at different steps of their development using onion-skinning-like display for key framing.
Rendering Curves And Sprites
Learn how to render light weight primitives and curves within Houdini and how to create special shaders for them. And when we say "create a shader", we mean build a real curve shader used to fake textured tubes! Learn how to use sprite rendering and discover some tips and tricks about sprite rendering that are the core of the classic particle effects softwares or painting programs.
Non-Photorealistic Rendering: Not only is this series of video the first one to cover l-system workflow in depth, but it's also the first one to teach you some real Non Photorealistic techniques (and by that, we do not mean how to find a built-in NPR shader in list, but how to really create non-realistic look!). For the first time, you will learn the workflow to render your trees as Monet or Cezanne painting, much like in the film "What Dreams may come" so that your painting gets animated!
Like in a Conference: As before, this video is interspersed with a lot of explanatory schematics to detail the advanced techniques, to recapitulate the workflow, to expose ideas, as if you were attending a professional cutting-edge Siggraph course. As usual, cmiVFX always give you the maximum amount of information and detail so that you never get lost in the procedural world.
Even if our primary purpose is to paint some plants on any surface, we introduce you to a brand new field, that we can call "Procedural Painting", which means that you link all the procedural machinery of Houdini to painting events through the use of CHOPS (channel operators). Like advanced "script painting" without any code of course! You could use these ideas to procedurally paint or grow railways, streets, particle effects or whatever pops into your mind. This is a first step in the world of CHOP real time procedural animation.
Push concepts of Painting Effects to the next level in Houdini. Learn how to interactively paint cluster of plants with parameters linked to pressure-sensitive devices such as Wacom tablets, like the number of generations of an l-system, or anything else! The interactive possibilities are endless. We give you workflow bricks to rapidly paint your vegetal landscape and ecosystem with some predefined plants (that you have created with the first video of course...)
Growing Ivy On Ruins
Do you want to cover your ruin with some L-system ivy? Then just paint it! Learn how to use wire deformers to grow your L-systems on any surface ( which is not possible with standard L-system rules). You can imagine an invasion of evil plants creeping around your objects. Of course you can paint on several objects at once with our method.
Nested l-systems is almost the ultimate workflow to deal with L-systems. The idea to plug l-systems one into the other has a lot of advantages: It breaks down your "code" into easier L-system bricks and creates a more controllable workflow (which becomes much more visual and yet remains completely editable). You can plug predefined l-systems one into another and then reach a level of sophistication unattainable with standard l-systems, having hierarchical deformations, controlling tree silhouettes, growths, etc!
The "Whomping Willow"
In the end, we put everything we've learned so far to create a detailed whomping willow, with twisted branches, using several different techniques combined together. On this, and with Houdini's non-destructive and reusable workflow, we create a path for ivy to grow using the methodology developed in the "painting ivy" section. This effect has been inspired from Harry Potter -like movies, or fairy tales with mysterious old forests.
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No Mirror below, Please!
No Mirror below, Please!