Time Travel: 2014

Benito Vasilyevich continued: “Perspective projection in particular is a typically computationally intensive projection, and the process involves trigonometric calculations.

It is not a simple trigonometric calculation like sin x and cos x. The trigonometric calculations involved in this process are usually accompanied by additional operations including matrix and vector multiplication. "

Benito Vasilyevich continued: "As the amount of recorded detail in a scene increases, the number of lengthy calculations used to render the scene will also increase, which is a great test for the CPU. .

Under normal circumstances, projection calculations involving general objects are very CPU intensive.

What's more, if it involves the raining scene, if perspective projection is carried out according to the method you mentioned.

The amount of real-time calculations will increase exponentially as the number of raindrops increases.

With all due respect, let’s not say that the A7 processor in the 5s is a desktop processor.

Even if the processing performance of the A7 processor is doubled on this basis, I am afraid it can barely meet this computing demand.

It's hard to make a meal without rice. If this method is really adopted, the existing CPU level will not be able to provide technical support at all.

Assuming that this is the method adopted by GRAY FOREST.

So under the current technical level, what kind of reaction will there be when running such a computationally intensive game?

These extra calculations will most likely require the game to be played at the reduced frame rates of mobile devices.

However, according to our actual testing, when the same 5s model is running the game "HILL CLIMB RACING", the frame rate will not decrease during the light rain in the rooftop scene.

This also verifies our previous judgment from the side.

That is, what GRAY FOREST used in "HILL CLIMB RACING" was definitely not the method of introducing a 3D rendering area and then constructing a folding book.

In addition, I think the method adopted by GRAY FOREST is not game rendering in the traditional sense.

Generally speaking, the steps usually taken when it comes to game rendering corresponding to 2D game screens are usually:

First obtain the 2D game screen data and then analyze the initial coordinates of the 2D game screen elements;

After obtaining the initial coordinates, an actual coordinate system of the 2D game screen element is constructed based on the initial coordinates.

Then, based on the actual coordinate system constructed above, the 2D game screen is mapped into a visual effect unique to the 3D game screen.

Then the data of the mapped 3D game screen must be cached in the cache.

When receiving the running instruction of the 2D game, it only needs to retrieve the data of the 3D game screen that has been generated in the buffer according to the running instruction.

At the same time, in order to enhance the expression, the retrieved 3D game images need to be further rendered.

The above process places high demands on the GPU, which must have powerful real-time rendering capabilities.

Although this approach works in theory, it only works on jailbroken Apple phones or Android phones after rooting.

But it is not realistic at all in a normal mobile phone.

After all, the GPU that an application can call is quite limited in most cases.

Therefore, I think GRAY FOREST definitely did not use this method in "HILL CLIMB RACING". "

Pa/Na/Ning: "Then what method do you think Gray Forest adopts?"

Benito Vasilyevich: “I can only guess that the way a person designs a game has a lot to do with his or her development style.

Although GRAY FOREST has risen very quickly, like a rising star, his development methods are quite sophisticated.

After all, before developing the game "HILL CLIMB RACING", GRAY FOREST had already developed three works.

These works have been verified by the market and are widely loved by game players.

GRAY FOREST who can achieve such results can be said to be an extremely experienced game developer.

And such people cannot create trouble for themselves out of thin air when it comes to specific game development.

Therefore, I conclude that what GRAY FOREST has adopted must be the simplest way.

In addition, not long ago, GRAY FOREST uploaded the code he designed for the previous development of "2048" on GitHub.

I didn't take it seriously at first because the form of this code was not very concise.

But it is definitely the most efficient to run on iOS.

In fact, for a simple game like "2048", even if the running efficiency is slightly different, it will not have a big impact.

But GRAY FOREST must build the most efficient one.

This shows that this person pursues high efficiency in his heart.

Such a person who blindly pursues efficiency must use the most efficient scene construction in designing the game "HILL CLIMB RACING".

The most efficient approach in 2D games is definitely not to introduce an additional 3D rendering area.

Based on efficiency analysis and judgment on the game screen.

I think GRAY FOREST uses a kind of visual deception to make the raindrops look layered in the rain scene. "

Pa/Na/Ning wondered: "Visual deception?"

Benito Vasilyevich: “Yes, it’s visual deception. Generally, we subconsciously think that ‘near is bigger and far is smaller’.

Therefore, when it comes to the layered structure of raindrops, you only need to express the raindrops in different sizes.

Of course, when it comes to such dense raindrops, it is absolutely impossible for GRAY FOREST to paint them drop by drop.

Normally speaking, a 2D picture is a picture with only X and Y axes, and no Z axis;

A 3D picture is a picture with X, Y, and Z axes.

The approach adopted by GRAY FOREST should be to introduce a virtual Z-axis into 2D games.

I'm guessing that GRAY FOREST specifically does this.

Because in games, things like raindrops are generally represented by particle systems.

[Generally speaking, particle systems represent techniques for simulating some specific blurring phenomena in three-dimensional computer graphics (CG).

The reason why these phenomena are called blurring phenomena is because it is difficult to achieve realistic game graphics using other traditional rendering technologies.

Phenomena that are often simulated using particle systems include fire, explosions, smoke, rain, sparks, fallen leaves, clouds, fog, abstract visual effects such as glowing trails, etc.

The core of the particle system is the particles with independent behaviors generated by the particle emitter, which together build the animation]

After introducing a virtual z-axis into the game.

In this way, when we build the layering of raindrops in game development.

It is completely possible for the particle emitter to give the weather particles (raindrops) a virtual depth value Z when emitting them.

During the entire life cycle of the weather particle, the virtual depth value Z remains unchanged;

There should be a function between the Z value and the state of weather particles (raindrops),

The function of this function is to scale the raindrops.

And this function will give different visual sizes and motion states to weather particles with different depth values.

Then the scaling transformation results are sent to the particle size display unit and particle motion status display unit respectively.

In this way, the weather particles in 2D games should theoretically have a layered feel.

Of course, this is just my guess. To know the real answer to the question, further analysis is needed.

Or, we have to seek answers from GRAY FOREST himself. "