Do you know what software is used to make visual effects and animations in film special effects? For example, Shrek, how to make these movies;

With the development of technology and ideas, CG fans in China are not satisfied with making some simple animations according to the examples in the software tutorial. Everyone is constantly trying new technologies and methods, determined to achieve moving pictures in movies and dreams. As a training institution for professional animators, DBS is also actively updating its training courses. To help digital dreamers with higher ideals realize their strange and novel ideas that keep popping up every day! However, there are very few anime fans who can participate in DBS training classes in China. In order to let those who have no chance to study with us experience the fun of creating digital special effects. We specially set up this technical column to discuss with you the production methods and ideas of visual effects that DBS and students tried together.

When it comes to film and television special effects production, there is a common conceptual misunderstanding in the domestic animation industry, that is, "three-dimensional animation can fix everything." When it comes to post-special effects, many novices interpret it as video clips like Premiere. In fact, these misunderstandings are all caused by vague concepts such as early and late stage, synthesis and editing.

Usually, in the division of digital film processing, 3D animation is similar to photography (video) and belongs to the category of pre-production. Because in the film and television special effects production, whether it is the digital image produced by three-dimensional animation or the video material shot by the camera, it is generally processed into the final special effects shot by the synthetic special effects production software. Finally, each shot and sound material is edited by nonlinear editing software until it is output as a complete film.

So the film and television special effects production we are discussing here. It is neither a simple three-dimensional animation nor a simple material editing. Instead, it includes the whole process of preparing three-dimensional production and photography (camera shooting) as preliminary materials, then processing digital special effects through synthetic special effects software, and finally editing and outputting special effects shots.

In the previous articles discussing the production of special effects, everyone paid more attention to the part of three-dimensional and synthesis software. In fact, in most of the special effects shots we have seen, the proportion of special effects shots realized by combining the previous shooting, such as scenery, blue screen, model, digital matte painting and so on. , far more than computer animation. This is also a fact that we want to "clarify" for you today-3D animation can't fix everything. However, whether you use three-dimensional animation or real props. It is an indisputable fact that the final effect needs post-synthesis software to complete. In the two stills about the production of Vertical Limit shown in figure 1, we can see that the stunt production team used various stunt means such as simulation model, artificial rock wall, blue screen background, miniature landscape, three-dimensional animation and so on, and finally synthesized the final shot through synthesis software.

In order to let people better understand the production process of movie stunts, we will analyze the production process of a stunt movie in combination with the domestic situation, and list in detail how to use limited resources to create our own movie stunts.

In fact, you will know it after you have personally experienced the special effects production technology. You don't need to spend tens of millions of dollars to make some amazing special effects, and you don't need to use expensive instruments like those introduced in various promotional videos. Suppose you are familiar with lighting, lenses, models, props and computer animation technology. Then most of the pre-stunt props can find ordinary carpenters and tailors for very little money. Even if it is a high-resolution stunt lens that rises to the size of a movie, only the camera and high-power lighting need to be upgraded.

Ok, let's take the experimental stunt film planned and shot inside DBS as an example. From script analysis, studio construction, stunt props selection, stunt team formation, stunt lens shooting, three-dimensional animation, post-synthesis editing and so on. This paper introduces a complete stunt movie production scheme. In this issue, I will discuss with you the preparatory work for this stunt movie. In future serials, we will discuss in detail the specific problems and solutions encountered in the production of various stunt shots.

1, script

To shoot any film and television drama or cartoon, the script is compiled before all the work. The purpose of DBS shooting this experimental film is mainly to let the students who already have the foundation of computer animation really experience the whole process of making a special effect film and the skills of making special effects. So the topic of the film is more about how to let students experience and practice more visual effects. Here we briefly list the outline of the story.

Stunt shot analysis

According to the story script, it is an important step to plan the stunt shots that need to be made in the whole film. Usually at this time, the visual effects director of the production team will analyze the script with the director, list each stunt shot, and determine the production plan and progress. Then the visual effects director will discuss the detailed methods and ideas of production with the heads of various departments of the production team to determine the production plan of each stunt shot. This process needs to test the visual effects director's rich knowledge background and good communication skills.

The following pages will introduce the technical analysis of the split and production of stunt shots in detail. In this issue, we will mainly introduce the means of production. According to the outline of the previous story, we can roughly understand that this psychedelic experimental film will involve the following special effects production methods:

(a), early shooting stunts:

Early shooting stunts are mostly manual stunts using traditional blue screens and simulation models. As shown in figures 2 and 3. Blue screen background has become a cheap means to save the cost of hiring audience actors in ordinary film processing. Hollywood added high-precision electromechanical control devices to the simulation model. Shooting stunts expected to be used in experimental films may include:

1, blue (green) screen background: used to shoot all kinds of indoor and outdoor stunt shots, 2, convenient for key synthesis in post-production;

3. Aerial photography: simulating the perspective of flying objects and the panoramic perspective of chasing scenes;

4. Simulation model: used to shoot local and disaster shots;

5. Slow shooting and fast playback: simulate the perspective of various high-speed running objects;

6, lens stunt: use the optical illusion inside and outside the lens to create special visual effects.

(2), three-dimensional animation stunts:

Three-dimensional animation stunts are mainly used for various effects that cannot be achieved by other methods in real shooting. At present, apart from monsters and spaceships, fireworks and environment are the most widely used. For example, as shown in Figure 4 and Figure 5, it is cheaper and more efficient to simulate the fireworks background and fantasy space that do not exist in large disaster films by using three-dimensional technology. It is expected that the three-dimensional technology used in the experimental film will probably include:

1, simulation role: used to simulate the shape and movement of unknown life;

3. Deformed objects: all kinds of deformed objects, randomly changing environment, soft life-like, making image distortion auxiliary channels;

4, particle special effects: flame emitter, starry background, dust, group animation, dynamic mask;

5. Simulated scenes: the prospect of inner senses, spaceships similar to life, fantasy plants 6. Things and buildings.

7. Lighting simulation: all kinds of light effect elements, volume light, flash, stereo lens facula.

(3), synthetic stunts:

Synthetic stunts in film production are generally classified as post-movies. If the early shooting and three-dimensional animation are summarized as the preparation of the early material, then the late synthesis stunt can be called the last level of output to the final product effect. The shot that needs to be completed by synthesizing special effects contains almost all the special effects of the whole film. As shown in figure 6 and 7. The most common effects include post keying, dynamic masking, various lighting effects and distortion. It is expected that the synthesis technology used in the experimental film may include:

1, blue (green) screen key: used for various characters and scenes in trick photography.

2. Delete and add objects in the color matching material;

3. Tracking: motion matching of shots or objects taken in the early stage, position reference of 3D and real shot material synthesis, reference of character decoration, position matching of lighting effects, etc.

4. Color matching: Match the colors of all real scenes, key figures and three-dimensional objects in the same shot. Make up for the color defects of various environmental influences in the previous shooting.

5. Distortion stunts: various temporal and spatial changes, character deformation, virtual space,

6. Two-dimensional particles: make up for the shortcomings of three-dimensional particles and modify local images;

7. Light effect and special effect filter: It provides infinite means for adding special effects and atmosphere to the material.

5. Indoor studio

When it comes to special effects studios, the terms and instruments involved may have little to do with computers. But if you are an expert in photography. Then you will be familiar with these things mentioned below.

(1) lighting equipment

Light source: the lighting used in film and television shooting is very different from that used in ordinary studios.

The first is the frequency: because the frame number standard of film machine and camera is 24_30 frames/second. The frequency of alternating current used by ordinary household light bulbs is relatively low, and stroboscopic and unstable lighting are easy to occur under this low-frequency lighting (the minimum synchronous frequency is required to be greater than 60Hz). Therefore, large-scale film shooting usually uses special high-frequency dysprosium lamps. Some large special lighting lamps also provide FM boxes, which can be used for frequency generation or frequency reduction. Provide stable high-frequency lighting guarantee for cameras (video cameras). In high-speed trick photography, the highest frequency of light can be adjusted above 2000Hz, so that a stable and saturated lighting effects can still be obtained when it degenerates.

Secondly, the power: the lighting of ordinary studios is generally around 300w W, and the standard of news lights for shooting is 1200w, while the big scene of outdoor filming is a high-power lighting group above10000 W.

Of course, the most obvious difference is that photography and video almost do not use flash. Therefore, more than 80% of the lighting in the photographic equipment city is not suitable for providing lighting for film and television drama shooting. Don't choose the wrong light!

From the perspective of low-cost production. DBS used several 2,400 W dual-lamp iodine tungsten lamp (news lights) for shooting lighting in the indoor studio. The advantages of this lamp are small size, flexibility and low price. For small and medium-sized indoor studio lighting, this kind of lamp is enough. Then some parts are equipped with ordinary 300w projectors to fill the light (light), so that the lighting hardware will not be subject to too many constraints.