Unity3d face Test (full)

I summed up some of the Unity3d high-frequency interview topics, hope can help everyone.

Limited to individual levels, with only a few reference answers attached.

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Data structures and algorithms are important, and graphics is important!

The big game company values the individual foundation, the comprehensive ability, also some value your actual work ability, looks at your demo.

High frequency question and answer questions:

A What is a render pipeline?

Refers to a series of necessary actions to be taken on a display to display an image.

Many of the steps in the rendering pipeline are to transform a geometric object from one coordinate system to another.

The main steps are:

Raster-------------------------------with

Two How to optimize memory?

There are many ways, such as

1. Compress the own class library;

2. Hide the objects that need to be used in the future, instead of destroy them directly;

3. Release the resources occupied by Assetbundle;

4. Reduce the partial number of the model, reduce the number of bones in the model, reduce the size of the map;

5. Using a light map, using multi-level detail (LOD), using shaders (Shader), using presets (Prefab).

Three, how to dynamically load resources? (sometimes also ask the difference, specific please Baidu)

1.resources.load ();

2.AssetBundle

Iv. What is a collaborative process?

Enables the execution of the current program by opening another logical process while the main thread is running. In other words, the open process is to open a thread. Can be used to control motion, sequence, and behavior of objects.

Five, which plugins have you used?

(preferably more familiar with a few plug-ins, ask when good answer)

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1. There are several ways to implement 2d games using Unity3d?

1. Use its own GUI;

2. Adjust the projection (projection) value of the camera to orthographic (orthogonal projection), regardless of z-axis;

3. Use 2d plug-in, such as: 2DToolKit;

What is the difference between a collider and a trigger in 2.unity3d?

Collider has the effect of collision, Istrigger=false, can call oncollisionenter/stay/exit function;

The trigger has no collision effect, and istrigger=true can call the Ontriggerenter/stay/exit function.

3. Necessary conditions for collision of objects

Two objects must have a collider (Collider), and one object must also have a rigidbody rigid body.

What is the difference between 4.CharacterController and rigidbody?

Charactercontroller comes with a capsule collider, which contains the properties of a rigid body;

A rigidbody is a rigid body that makes an object characterized by a rigid body.

5. In the whole process of collision, there are several stages, the corresponding functions are listed separately

Three stages

1.OnCollisionEnter

2.OnCollisionStay

3.OnCollisionExit

In the physics engine of 6.unity3d, there are several ways of exerting force, which are described separately.

Rigidbody. Addforce/addforceatposition, all in the Rigidbody series function.

7. What is a chain joint?

Hinge Joint, can simulate two objects with a chain connected together, can maintain two objects within a fixed distance of each other moving without force, but reached a fixed distance will produce tension.

8. What is the function of rotation of the object itself?

Transform.rotate ()

9. What functions are used to rotate objects around a certain point?

Transform.rotatearound ()

10.unity3d provides a class for saving and reading data (playerprefs), listing functions for saving and reading shaping data

Playerprefs.setint () Playerprefs.getint ()

11.unity3d provides several types of light sources, which are the different?

Four kinds.

Parallel light: directional light spot

Spotlight: Spot light lighting: Area Lights

12.unity3d scripts from Wake-up to destruction there is a relatively complete set of life cycles, please list the system comes with several important methods.

Awake-->start-->update-->fixedupdate-->lateupdate-->ongui-->reset-->ondisable--> OnDestroy

13. What system functions are the physical updates generally placed in?

Fixedupdate, every fixed frame is executed once, and update is different fixedupdate is rendered frame execution, if your rendering efficiency is low, fixedupdate calls will be followed down. The Fixedupdate comparison is applicable to the calculation of the physics engine because it is related to each frame rendering. Update is more appropriate for control.

14. What system function is placed on the action of moving the camera, and why is it in this function?

Lateupdate, which is called at the end of each frame, is only tuned after all the update finishes and is more appropriate for the execution of the command script. Official online example is the camera follow, all the update operation is done before the camera, or there may be a camera has been pushed, but the perspective of the role of the empty frame appears.

15. What do we need to do to save memory when we need to create an object frequently in the game?

Use the Prefab object prefab, and then copy the creation.

16. What happens when you place multiple camera in a scene and are active at the same time?

The game interface can see a mix of many cameras.

17. Describe the role of prefab and describe how to use it properly in a mobile device environment.

Prefab is used when instantiating, mainly for objects that are often used, the properties are easy to modify.

18. How do I destroy a unityengine.object and its subclasses?

Use the Destroy () method;

19. Please outline how to safely migrate asset data between different projects under Unity3d, please list three ways?

1. The Assets directory and the library directory can be migrated together

2. Export the Package

3. Assets Server features with Unity

20. Please describe what kinds of game animations, and how it works?

There are mainly joint animation, skeletal animation, single mesh model animation (Keyframe animation).

Joint animation: The role is divided into several independent parts, a part corresponding to a grid model, part of the animation connected to a whole animation, the role of more flexible, Quake2 use this animation;

Skeletal animation, widely used in animation, the integration of the advantages of the above two ways, the skeleton by the role of the characteristics of a certain level of structure, joint, can do relative movement, skin as a single mesh outside the skeleton, determine the role of the appearance;

The single mesh model animation is composed of a complete mesh model, which records the original position of each vertex and its change amount in the key frame of the animation sequence, then the interpolation operation realizes the animation effect, and the character animation is more realistic.

21. Describe why the data loss occurs on the component in the Unity3d

Objects that are bound to the assembly are usually deleted.

How 22.alpha Blend Works

Alpha Blend achieves transparency, but only Alpha for a block of regions, and transparency can be set.

23. Write a calculation formula for diffuse in light calculation

Diffuse = kd x colorlight x Max (n*l,0), KD diffuse factor, colorlight light color, N unit normal vector, L from point to light source unit vector, where N and L are multiplied, and if the result is less than or equal to 0, the diffuse is 0.

What is 24.Lod and what are the pros and cons?

LOD (level of detail) multi-layered detail is the most commonly used game optimization technique. It determines the resource allocation of object rendering according to the position and importance of the model, reduces the number of non-important objects and the detail degree, and obtains the efficient rendering operation.

25. Two ways to determine the shadow and how it works.

26.Vertex shader is what, how to calculate?

Vertex shader

What is 27.MipMap, function?

MipMapping: There are commonly used techniques for mapping rendering in three-dimensional computer graphics, in order to speed up rendering progress and reduce image aliasing, the map is processed into a series of pre-computed and optimized pictures of the file, such a map is called mipmap.

28. Machine Test: Two Select one

1. Implementing a third role controller in code

2. Realize the function of crane hanging object

29. What is the inverse rotation animation method?

30. What are the properties of the object for collision detection?

31. What are the commands for acquiring, adding, and deleting components?

Get: Getcomponent

Added: addcomponent

Delete: Destroy

The 32.animation.crossfade command function is: (C)

A. Animation amplification B. Animation conversion C. Animation fade in to other animations

The 33.application.loadlevel command is: (A)

A. Loading A level B. Loading A level asynchronously C. Load action

34. What are the commands for debugging records to the console?

Debug.Log ();

35. What is the editor class storage path?

Under the Assets/editor folder in the project directory.

36. What is the command to create a window that can be dragged using the native GUI?

Gui. Dragwindow ();

37.localPosition and the use of position difference?

Localposition: The location of its own position, relative to the parent's transformation.

Position: Position in world coordinates transform

38. Meaning Connection

Mathf.round interpolation

Mathf.clamp rounding

MATHF.LERP restrictions

39. Write a timer tool, starting from the hour, the format is: 00:00:00

40. Five ways to write a animation

41. How to get an object on the script method

Gameobject.getcomponent<> ();

42. On the machine title: Use the mouse to achieve in the scene drag objects, with the mouse wheel to zoom (with a cube).

43. Describe the point multiplication of vectors, the cross-multiplication of vectors, and the geometrical meanings of vector normalization.

The geometric meaning of the point multiplication is to calculate the angle between the two vectors and the projection in a certain direction;

The geometric meaning of the fork is: Create a vector perpendicular to the plane, triangle, or polygon

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Unity3d face Test (full)