• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
Orymus3

Unity
2D or 3D physics for a top-down 2D ARPG in Unity?

9 posts in this topic

Hi,

 

I'm currently setuping my project in Unity. It will be a 2D action RPG.

Though all of the visual will be 2D sprites, I'm concerned that I want to implement features such as jumping over certain obstacles, have some bridges pass over the floor at different heights, and it currently feels like using 3D physics behind the scenes would be much simpler, despite the game being entirely 2D from a visual standpoint.

 

Anyone here tried doing anything a top-down game in Unity? What did you use and why?

0

Share this post


Link to post
Share on other sites

You can use 2D graphics to emulate 3D objects, but it's really not going to work out for you if you're trying to use 2D physics to emulate 3D physics.  Sounds like you already know the answer to your question.

 

That, and unless you're going crazy with the number of objects that interact with one another, the performance gap between 2D physics simulation and 3D physics simulation isn't big enough to justify shooting yourself in the foot over.

0

Share this post


Link to post
Share on other sites

So, you assessment is that, regardless of the actual visual output (2d in this case), dropping the Z axis is not a sufficient performance-gainer to justify limiting myself.

That being said, it does come with an added complexity that I need to handle to process collisions.

 

I just feel choosing 3d for a 2d game feels like refusing to use a set of tools optimized for most of what I'm trying to do save for a few things, so I end up handling everything in a 'custom' way because of the few situations that would benefit from that support...

0

Share this post


Link to post
Share on other sites

I'm by no means an expert in Unity so I'd like to recommend a little sodium chloride with this reply, but in my experience using 3D graphics for a top-down or side-scrolling (parallax) 2D game is unlikely to affect performance much. In fact, the effect would probably be an improvement. Here's my reasoning:

 

In any robust game engine or environment, graphics are usually mixed along alpha channels (etc.) during game play -- characters & obstacles layered on a separate background, etc. In 3D, this is complicated with the addition of a Z axis which requires additional depth management including clipping, occlusion, and so on.

 

At the same time, any 3D engine worth a spit will be efficient, meaning it will not waste too many cycles trying to figure out things like clipping when the graphics blocks are basically just flat planes perpendicular to the Z axis. In effect, the game is simply shifting around postcards on which you probably don't want to apply lighting effects, meaning much of the complexity of a full 3D environment is reduced.

 

Additionally, 3D engines tend to boast their polygon rendering abilities so you know roughly what kind of performance you're likely to get. And beyond this, 3D engines often make direct use of graphics hardware which can greatly increase both rendering speed and free up the main processor for other functions (handling A.I., collision detection, etc.) 2D engines usually use the main computer/device processor so they can boast greater compatibility, but at the cost of raw power and speed.

 

In Adobe Flash, for example, we have had robust 2D graphics since pretty much the inception. Many optimizations have been made to the software to make it efficient, and it was pretty darned good until Adobe introduced direct GPU support. As a result, frameworks like Starling popped up that boasted the same capabilities as Flash 2D but with the ability to handle a lot more while simultaneously freeing up the CPU. In other words, Starling is a 2D game engine that uses Flash's newer 3D capabilities, analogous to your question. The answer that Starling provides is quite clear: 2D games can realize significant performance enhancements (plus easier code/effects), by using a 3D engine.

 

Back to Unity, I'm fairly certain that the same GPU acceleration is used which would lead me to believe that you would be better off using the full 3D engine to create a 2D game; the performance improvements alone would be worth it. Also, as you mentioned, 3D engines tend to have a lot of functionality pre-built -- physics, collisions, etc. It's nice to know how these work but if you're more concerned with actually building the game, these topics are probably best saved until later.

 

My two cents smile.png

Edited by Patrick B
2

Share this post


Link to post
Share on other sites

Thanks, but I think my concern doesn't really lie with performance, but rather, ease of use for game logic (handling collisions, etc.).

Assuming I want to have stuff like jumping and overpass bridges/mezzanines, I felt 3D makes it easier to handle, but that would also mean I need to attach 3d collision boxes to actual 2d sprites, which feels a bit counter-intuitive?

0

Share this post


Link to post
Share on other sites

Try both, there's no wrong one.

 

Really, you're using Unity, it's really easy to try both approaches, you don't even need to remove one to create the other, just disable the 2D or 3D collision components and enable the others, you don't even have to replace code since each 3D collision callbacks has a different name in 2D (OnTriggerEnter and OnTriggerEnter2D, etc). Setup some test scenes with the things you have in mind (jumping over enemies, different heights, etc) and try them if you're not sure.

 

Anyway, for a 2D game I think I would go with 2D collision detection and use the z axis values or some flags to check if the collision should be considered or not, it doesn't look like too extra work and maybe you can prevent weird bugs related to the 3D collision volume that you wouldn't notice in a 2D view. Also, 3D and 2D physics use a different axis for gravity and that could lead to more weird bugs, so that's another reason I'll do it in 2D.

2

Share this post


Link to post
Share on other sites


ust disable the 2D or 3D collision components

 

Wouldn't my code still run actual vector2D vs Vector3D ?

I'd still need to change the code to switch between the two, no?

 


Anyway, for a 2D game I think I would go with 2D collision detection and use the z axis values or some flags to check if the collision should be considered or not, it doesn't look like too extra work and maybe you can prevent weird bugs related to the 3D collision volume that you wouldn't notice in a 2D view. Also, 3D and 2D physics use a different axis for gravity and that could lead to more weird bugs, so that's another reason I'll do it in 2D.

Makes sense. I was going to do something along these lines in 2D.

 

Thanks.

0

Share this post


Link to post
Share on other sites

 


ust disable the 2D or 3D collision components

 

Wouldn't my code still run actual vector2D vs Vector3D ?

I'd still need to change the code to switch between the two, no?

Even in 2D, Unity puts everything in a 3D world, so the game objects would have a position with x, y and z values in both cases (Vector3). You'll always see the 3 components in the editor, and if you change your scene view from 2D to 3D you'll see that the z value is being used.

 

Also, you can have one script that handles 2D collision and another that handles 3D collision so you don't need to change code, just enable/disable those too depending on what you're testing, and then call methods of another script that does the logic you want for a collision.

1

Share this post


Link to post
Share on other sites


Also, you can have one script that handles 2D collision and another that handles 3D collision so you don't need to change code, just enable/disable those too depending on what you're testing, and then call methods of another script that does the logic you want for a collision.

 

Ok yes, that's what I meant. 

 

Thanks.

0

Share this post


Link to post
Share on other sites

Use 3d physics. 2d physics in Unity are more catered towards sidescrollers, for example gravity is either x or y axis so you would have to use kinematic rigidbodies and handle jumping yourself. Methods like transform.LookAt() don't work out of the box. etc. I made couple of top down prototypes a while ago, in the end I switched to 3d physics. The performance gain with 2d was so marginal it was not worth it even on mobile.

 

Also, there are things not available with 2d physics, like particle collision detection.

 

 

 

Thanks, but I think my concern doesn't really lie with performance, but rather, ease of use for game logic (handling collisions, etc.).

Assuming I want to have stuff like jumping and overpass bridges/mezzanines, I felt 3D makes it easier to handle, but that would also mean I need to attach 3d collision boxes to actual 2d sprites, which feels a bit counter-intuitive?

 

Forgot to mention that 3d physics with sprites felt a lot more comfortable to me, as you can give volume to the colliders.

Edited by dissid
0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0

  • Similar Content

    • By ilovegames
      The boy and the Golem were friends for a long time, and have traveled together.
      In search of the boy's father, they go to where he grew up, places now devastated by war.

      The player can at any time switch the characters and manage to solve a specific task.
      The boy is small and weak but is clever and an archer.
      Golem is big and strong, but slow, and prefers melees.

      The game includes the boom (required for archery) and apples (to restore his health). Golem Health is restored automatically. On the way our characters will encounter enemies and locked doors, and to open the door you must activate rock platforms nearby (decorated with blue stones that are activated by Golem from on the ground, and green that are activated from an arrow launched by the boy). Some doors will open only with simultaneous activation of a few (two or three) different types of stone platforms.

      Controls:

      Movement - W, A, S, D
      Switch character - Tab
      Direction of impact \ shot - mouse (cursor position)
      Attack:
      Golem - LMB
      Boy - When sandwiched RMB (Aim), press the LMB, for a shot
      Jump - Space



      TheBoyAndTheGolemSetup.exe
    • By KaiZerg
      Dear Colleagues,
      Can you please advise on the issue below:
      I have got several Folders(paper), to keep cheat sheets, practical guides, Lists of sequences ect.
      What is the best way to separate Folders?
      1)
      -Unity all
      -Unreal Engine all
      2)
      -Game art
      -Game Design
      -Game Engine
      -Game Programming
       
    • By suerozcelik
      Hi everyone, My name is Arda Süer, i’m a game developer and producer of Pocket Universe : Create Your Community. Pocket Universe is on pre-order and soon the early access to Steam. I need your help and I want to introduce you to my game. Please read the game story and website content etc. If you have any suggestions tell us and we can develop. Example:"Story is good but you need more faction","You need add bla,bla to the game". Anyway I will put links here to help you to understand Pocket Universe. Story : http://www.pocketuniversegame.com/?page_id=7 Features : http://www.pocketuniversegame.com/?page_id=180 Factions : http://www.pocketuniversegame.com/?page_id=54 Press Release : http://www.pocketuniversegame.com/?page_id=237 If you want to help more, please buy my game Kinguin : https://www.kinguin.net/category/38680/pocket-universe-create-your-community-pre-order-steam-cd-key/ G2A : https://www.g2a.com/pocket-universe-create-your-community-steam-key-global-i10000070716001 Press Relase.rtf
    • By NA-45
      I'm currently working on Metroidvania style game that I was inspired to start by Hollow Knight and Beksiński's art.

       It's built in Unity using C# and has quite a bit done already.  I'm handling the programming myself and have a working model (besides combat which is a WIP) that can be expanded greatly depending on where we decide to take the project.  You can see the current test area here: https://streamable.com/mp5o8  Since I'm not artistically gifted, its all rectangles but can easily be skinned once we've desired on designs.
      I have professional experience using Unity and C# working on both a released game and a prototype as well as having extensive Java knowledge.  I also dabble in Python with a little bit of C++.
      I have worked on and completed many projects before, the most recent being a 2D stick fighting game written ground up in Java Swing (don't ask why): https://www.youtube.com/watch?v=V4Bkoyp_f0o
      I'm looking for a 2D artist (potentially more than one) to create concept and game art and a designer/writer who can help flesh out the story as well as map out and create challenging and eye catching areas.  I can handle most if not all of the programming side of things though if there is anyone who is extremely passionate about this sort of thing, I'd consider splitting the load.
      The end goal is a completed game that can be sold however profit isn't really a concern to me as it's mostly a labor of love from my part.  Any profits would be split between team members however that's pretty far off so don't make that a reason to join.
      ______________________________
      The story I have in mind is something like this:
      A man wakes up in a chasm that stretches seemingly endlessly in both directions lined with enormous statues.

       He discovers a temple with text above a closed gate that tells of the failed kingdom that lies below.  After finding a way around this, he drops down into the subterranean kingdom.  Adventuring through the labrynth below, he comes across different cities in which the residents succumbed to different sins such as Greed, Wrath, etc.  Each city tells a story of how its fixation on something lead to their demise leading up to a fight with the personification of their mistake.
      ______________________________
      An very rough idea for Waterways, a potential area:
       - To enter you must be wearing a pair of glasses that you find somewhere earlier in the ruins.  There are similar glasses found in every home.  Everything appears incredibly beautiful however something seems wrong.  After triggering some event, the glasses break and it's revealed that the glasses are made of some sort of stone that makes everything appear differently.  The city is in ruins and absolutely disgusting as everything was neglected.  
       - The only thing that remains intact is in the center of the city, an incredible statue of a goddess holding up a large sphere of the same material that was used for the glass.  You slowly learn the story behind the statue: the goddess came from the sea that the city lies on and brought prosperity to them.  
       - After opening up the the temple of the goddess that lies right on the edge of the waters, a giant sheet of the glass covers an opening in the back of the temple that reveals the goddess behind it.  You shatter the glass and it becomes apparent that the goddess is actually a disgusting creature half beached and mostly immobile that appears to secrete the material that makes up the glass. Fight ensues.
      ______________________________
      The combat is pretty up in the air and part of the reason I need a designer to bounce ideas off of but I think it will be something like this:
       - 4 orbs equipped at a time
       - 2 orbs selected at a time
       - Pressing the cast button will cast a spell determined by the 2 orbs that are selected
       - Spells cost mana however you can use spells with 0 mana and it will cost health instead
       - These spells in addition to being useful for combat, are the Metroidvania "gating" metchanic.  For instance, one of the conceptualized spells is a water orb + water orb to create a ice pillar that can be either used to block projectiles/enemy paths or to jump on to reach high areas
      ______________________________
      If you're interested or have any questions, contact me through discord.  My id is NA-45#3692. 
       
    • By Qwertyman
      My game (built on the Unity platform, making use of EZ GUI) requires players to log into Facebook. However, when the player is using a language other than English on Facebook, I'm unable to display the localized Username (which is the same as the FB Username) within the game. Any ideas on how this can be tackled?
      PS: Detecting the OS language doesn't really help here because, for all you know, the player might be using one language for the OS, but another one for their Facebook, so.... 
      TIA!
  • Popular Now