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[RCIX]

Reference Frame

This is a small platformer project that merges two things: post-processed lofi pixel art, and an innovative mechanic (more on that below).

What is this?
A platformer, obviously But the special bit is this: One has the ability to manipulate the "reference frame" your velocity (and position, in some cases) is "compared" to. In this case, your final velocity/position is of course compared to an absolute reference frame, but you can also choose a moving object (or still one in the case of position) to have your motion/position be relative to.

So if there's a wide gap you need to get across, but the moving platform is too far down in the gap, you could jump and then change your reference frame to the platform so you have enough forward momentum to cross. Or if you need to get past a barrier, you can attach your positional reference frame to a special object and then change it again to one past the barrier.

What tools are you using?
Currently using XNA 3.1 and Visual Studio 2008 for code, with Photoshop CS4 for the graphics.

Current plans
Add enemies
Add a couple more powerups
Add level backgrounds

Downloads
Platforming tech demo: Contains a small playground demonstrating the platforming as well as the reference frames concept

[grayfox88]

I like the sprite glow effect, but I'm not sure what you mean by reference frame. Could you elaborate?

[RCIX]

It's a reference to physics, which uses frames of reference to base measurements of motion/position/rotation off of. The trick in this game will be that your velocity or position doesn't change with respect to different reference frames (but your overall "final" position/velocity is compared to an absolute reference frame). I'll see what I can do to clarify the OP with this info!

Edit: that may not make sense, if it doesn't then it'll be harder to describe than i thought

[RCIX]

Been fairly busy today, but I'll at least try and mock up a test stage in Tiled. I did complete the grass tileset yesterday, here's both the png and a screen from Tiled with all the elements used:



I'll do more screenshots once I bring it (and the associated level parsing code) into the project.

[FK in the Coffee]

So, if I start a jump in one area, and change my reference frame to another area, I'll still be going up with the same acceleration I had when I started jumping?

[RCIX]

Yeah, manipulating the positional reference frame is much like a 2d version of a Portal. I'll have to get a rough prototype out ASAP so I can show off the tech!

[RCIX]

Day 3:
 * New progress image!
 * Scrapped the idea of using Tiled to create/edit maps (too heavyweight for my purpose)
 * Designed a basic custom map format (using the universal standard: images )
 * Made test map incorporating most features
 * Partially re-did grass tileset
 * sort of got map importing working
   * The code that maps solid blocks of ground into all the right tiles to create seamless tiled structures is borked right now
   * "Entities" aren't shown ATM (basically anything that moves or reacts to player input)
   * This is to say nothing of having a spawn point (forgot that in the level design.... :x) or even a player to spawn
   * It's a start though!

[RCIX]

Day 4:
 * New progress image!
 * Fixed tile calculation code
 * Almost re-completed grass tilesets

[RCIX]

Ok, so daily posts don't work >.> I've rigged up the platforming mechanics, which have been slightly re-specced to account for limitations in the physics engine I use:
 * Character cannot jump, instead he can climb walls
 * Scrapped moving single-tile platforms
 * Scrapped stationary single-tile platforms

I hope to have a demo out by Wednesday showing off the primary features!

[RCIX]

Ended up scrapping the use of said physics engine and rolling my own collision code, which took up most of today's working on this, but is a lot more stable now. Jumping is back in, as well as both types of platforms.

There's a couple of things left to do before the demo release, which aren't trivial but shouldn't take too long.

[gecko]

the screenshot form the first post is looking AWESOME.

hope to see it released, great work!

[Geeze]

I foresee physics abuse and sequence breaking. I like it.

Let's presume you could pickup and throw stuff. What would happen if you change your reference frame to a rock, pick it up and start moving?

[RCIX]

I foresee physics abuse and sequence breaking. I like it.

Let's presume you could pickup and throw stuff. What would happen if you change your reference frame to a rock, pick it up and start moving?

I wasn't planning to add anything you could pick up, but hmm. Without caps on your movespeed you'd either start a feedback loop that sent you careening at ridiculous speeds, or just get really really fast acceleration, not sure which. I just might have to try something like that. It would probably be more of a thing where attaching your reference frame to the rock transfers your motion to it (for cool remote telekinesis throws and stuff), but yeah.

A big limit will be that you can only maintain a reference frame link to something that's on your screen, to prevent crazy teleports and continual rythmic velocity disruption type stuff.

[RCIX]

Aight, wasn't able to finish enough to get out a demo quite yet, but I have made significant progress:
 * Settled on a player sprite (at least for now)
 * Tweaked code to support levels of size >1 screen (including using a canned camera class i've written previously)
 * Progress image updated!

I also did a mockup showing off the planned UI and several elements not yet implemented:

Done in photoshop, so no postprocessing effects.

I've also settled on a large portion of the game design, and you can spot a good chunk of it in that mockup. It by no means details everything though, and I'll reveal more at a later date

[RCIX]

I've added in the last feature I want for an initial tech demo, I just have to track down why it's not loading the latest level data () as well as make something resembling a normal level. I have more planning to do, and once i finalize enough of the design I'll do a nice big post explaining it all.

This is my first project which I actually feel like I could complete! I just hope I won't have to eat my words

[negativeview]

When Portal was first expained to me, I thought it was this game. I'll be very interested in playing this if it's anything like what I thought Portal was going to be.

[RCIX]

Sorry it's been so long! I've finally completed the demo, which you can download here. In the event that the game is too laggy, create a shortcut to the exe and append the command line argument "-nopostprocessing" (without the quotes).

Requires XNA 3.1 and at least PS 2.0 to work.

A bit of a guide:
 * Movement is arrows, jump is space
 * X selects a reference frame
   * When you select a moving platform as your reference frame, you gain its velocity
   * Selecting a position anchor as your reference frame allows
     you to select another, at which point your position is modified
     based on the difference between the two anchors
     * You cannot use this to warp off-screen or into solid ground

Next up on my list is to implement health, energy, and powerups. Or maybe enemies/hazards. Hmm. Gonna need to re-write the OP soon too

[rek]

This thread needs some video for those who can't (or just won't  ) play the demo.

[gecko]

I thought the same when i saw i needed to install the XNA, .NET and all that stuff 

[RCIX]

Ill see what I can do.