Blender 3D: De Novato a Profesional/Lo Que Blender Puede Hacer

En este módulo, aprenderás lo que hace Blender, tanto en términos del producto (imágenes) como del proceso (modelado 3D).

Blender es un paquete de software libre para crear gráficos "tridimensionales" (3D) (también conocidos como gráficos por computadora o “CG”), incluidas imágenes fijas, juegos y video.

Mientras que el producto final de la mayoría de los proyectos Blender es una imagen ráster bidimensional (2D) sobre una superficie plana (ya sea un monitor, una pantalla de cine o una hoja de papel), excepto las aplicaciones de realidad virtual montada en la cabeza, se dice que las imágenes son "3D" porque exhiben la ilusión de profundidad. En otras palabras, alguien que mira la imagen puede decir fácilmente qué partes deben estar más cerca y cuáles están más lejos.

Un Ejemplo

Aquí hay una imagen fija realista que fue creada con Blender.

"Una Casa Solitaria", de Mayqel

Mira de cerca el edificio.

• Debido a que está oscurecido por el edificio, puedes ver que la ladera arbolada está "detrás" del edificio en lugar de al revés.
• La forma en que los bordes superior e inferior de la pared frontal parecen converger hacia la base del árbol te permite juzgar el ángulo entre la pared frontal y tu punto de vista.
• Tu cerebro interpreta las partes oscuras de la pared como sombras, lo que le permite estimar de dónde viene la luz, incluso si el sol está fuera del marco de la imagen.

Mientras que una ilusión de profundidad se puede crear a mano con el software de gráficos 2D (¡o un pincel!), Blender proporciona una manera mucho más fácil.

Es probable que la casa solitaria nunca haya existido fuera de la mente del artista. En lugar de construir un gran escenario en un terreno rural en Alemania, esperando la luz correcta y fotografiándolo, el autor construyó una escena en un mundo virtual en 3D, uno dentro de una computadora. Esto se llama CGI (Computer Generated Imagery, Imágenes Generadas por Computadora). Entonces él o ella uso Blender para renderizar la escena (convertirla en una imagen 2D). Puedes ver más de lo que Blender puede hacer en la galería de Blender: http://www.blender.org/features/

Pasos en el Proceso de Producción 3D

Producir una imagen como la anterior implica dos pasos principales para comenzar:

• Modelado, que es la creación de su mundo 3D en miniatura, también conocido como modelo o escena. Esto implica definir la geometría de los objetos, haciendo que parezca que están hechos de materiales particulares, configurando la iluminación, y definiendo un punto de vista de la camara.
• Renderizado, que es la propia generación de la imagen del mundo desde el punto de vista de la cámara (tomando una "fotografía" de la escena, si quieres), para que tu audiencia disfrute .

3D es usado frecuentemente para producir no solo simples imágenes estáticas, sino animaciones también. Esto requiere algunas etapas adicionales:

• Rigging — setting up a rig, namely a way of deforming (changing the shape of) a character in various repeatable ways to convincingly mimic joint movements, facial expressions and other such actions of real-life people or animals.
• Posing — choreographing the positions of the objects and their parts in the 3D scene over time, using the previously-created animation rigs
• Rendering now involves creating a whole sequence of frames representing movement over time, rather than just a single still frame.

But that’s not all. There are frequently additional processes to embellish the results of the above, to make them look more realistic:

• Sculpting — a more organic form of modelling objects by shaping them as though they were made out of clay. This produces more complicated, irregular shapes which mimic real objects found in nature, as opposed to clean, simple, geometrical ones which mostly only exist in the world of mathematics.
• Texture painting — You’re probably familiar with programs that let you paint an image on a 2D digital canvas. Such programs are commonly used in 3D production, to create textures which are “wrapped” around the surfaces of 3D objects to give them a more interesting appearance. 3D programs also often allow direct painting on the surfaces of those objects, so the effect of the design can be observed immediately, instead of having to go through a separate paint-on-a-flat-surface-then-wrap sequence of steps.
• Physical modelling — simulating the behaviour of real-world objects subject to real-world forces, for example hard balls colliding, soft cloth draping itself over an obstacle under gravity, water flowing and pouring. Mathematical formulas are available for these that give results very close to real life, all you need is the computing power to calculate them.
• Motion capture, or mocap: producing convincing animations, particularly ones that look like the movements of real people (walking, running, dancing etc) can be hard. Hence the technique of capturing the motions of live actors, by filming them with special markers attached to strategic points on their bodies, and doing computer processing to track the movements of these markers and convert them to corresponding movements of an animation rig.
• Compositing — this is where 3D renders are merged together with real photographic/live-action footage, to make it look like a rendered model is in the middle of a real-world scene, or conversely a real live actor is in the middle of a rendered scene. If done with proper skill, in particular due care to matching the effects of lights and shadows, the viewer becomes unable to tell what is real and what is not!

And just to add another complication to the mix, there are two kinds of rendering:

• Real-time rendering is rendering that has to happen under tight time constraints, typically for interactive applications like video gaming. For example, most gamers nowadays consider that the screen has to be updated 60 times per second in order to render smooth motion and respond quickly enough to player actions. These time constraints impose major limitations on the kinds of rendering techniques that can be used.
• Non-real-time rendering is where the time constraints are not so tight, and quality is the overriding factor. For example, when producing a single still frame, it may not matter so much that it takes minutes or hours to do so, because the beauty and detail of the final image is worth it. When rendering a Hollywood-quality movie, it may still take hours per frame, but the use of a renderfarm of hundreds or thousands of machines, all working on different frames at the same time, allows the entire sequence to complete in just a few weeks.

But wait, there’s more: There are also some areas, which might be considered to be stepping outside of traditional 3D production work, where Blender provides functionality:

• Video editing — having rendered your animation sequences and shot your live-action footage, you will want to combine them in a properly-timed linear sequence to tell a coherent story.
• 3D printing — Though still in its early days yet, many people are already experimenting with creating objects using 3D printers. The shape data may be obtained from real objects with 3D scanning, or it may be created from scratch using 3D modelling, or you can even combine both processes.

Blender is a capable tool for every single one of these processes. There’s quite a lot there, isn’t there? But don’t be too intimidated: this Wikibook will take things step by step, and you will be able to produce some fun stuff from early on.

Recursos Adicionales

• Renderizado 3D en Wikipedia.
• Comparación de softwares de gráficos 3D por computadora en Wikipedia.
• Imagen generada por computadora en Wikipedia.
• Percepción de profundidad en Wikipedia.
• Galería de arte de Blender
• Página principal de Blender