Do Ren'py support sprites / spritesheets? [SOLVED]

[Luxliev]

Do Ren'py support sprites / spritesheets? As in subject.

[PyTom]

Yes, but to be honest they're less efficient than just loading from multiple files.

[Luxliev]

Loading multiple files is more efficient? That's good news to me but if it's not a problem can I know why? Almost everyone says that spritesheets have better performance and use less space.

I just want to be sure before I'll write code. I'll probably use more than hundred images for animation and I have plans for mod support.

[nyaatrap]

I'd also like to know which is efficient:

Code: Select all

image animation:
    "A.png"
    pause 1
    "B.png"

image animation:
    "spritesheet.png"
    crop rectA
    pause 1
    crop rectB

[Sword of Akasha]

I'd recommend using different images instead of sprite sheets. I like it much better as an artist since it allows greater freedom in expressions regarding not just the face but the body. Posture and etc can be easily set to correspond to an emotion. Sprite sheets that only change the face are kind of bit boring to me.

[PyTom]

Well, when I said spritesheet, I meant Filmstrip, which nobody uses anymore. That loaded the entire image into memory, and then cropped it in a way that meant it doubled memory usage.

I don't have that much a sense of which - if any - of the proposed methods are faster. My general thinking is that Ren'Py is usually fill-rate limited, so once the images are loaded (which occurs in the background) you're going to get the same performance.

[Luxliev]

I like it much better as an artist since it allows greater freedom in expressions regarding not just the face but the body.

Spritesheets do not limit you in any way. What they are is one big image for character instead of tens or hundreds. Also because there is only one image to load it's much bettter for performance and memory usage at least that's what I was told. Example below:


For simple python code you can make all frames used for animation in the same size:


You can also see examples of that in RPG Battle Engine in Cookbook section.

Good tutorial on spritesheets:
http://gamedevelopment.tutsplus.com/tut ... edev-13099

My general thinking is that Ren'Py is usually fill-rate limited, so once the images are loaded (which occurs in the background) you're going to get the same performance.

So all images are loaded on the fly? I'm really curious how this exactly work in Ren'py. Is there some link explaining this? For example when I replaced image when game run and game loaded it again it was the same image as before change, not the new one. So are new images loaded after all images loaded exceed fill-rate limit?

[Counter Arts]

I think spritesheets are generally used in traditional games since textures have to be a certain size multiple, and then you just choose texture co-ordinates for quads.

The predictive algorithms are in renpy that "look-ahead" to potentially used images are used to load images that are upcoming. If you heard of "branch-prediction" in CPU architecture you'd get a similar idea only with images.

EDIT: I'm going to guess a little bit about the predictive loading in Ren'py. In traditional games, most vary with what they need to load and when. Visual Novel actually have quite similar loading behaviours and not huge amounts of variants in the immediate future.

AAA studios usually load absolutely everything they need in a level into memory (after working 512 MB of RAM for a decade). This is the ensures that the game console won't have to stop the action to load a texture or something.

Then there is something like "load-on-demand" textures and resources where you load something from disk when the game calls for it. You don't quite have to worry as much on fitting everything in RAM. However the game will literally stop, load the texture, then resume everytime a texture is not loaded but needed to draw something.

Ren'py looks ahead in the script around 10-100 lines. It check for any graphical resources and loads them ahead of time. If there is a "branch" then it actually looks ahead all the possible branches and loads a little bit of each of them.

At least my in my guess... this is how I think it works.

[Luxliev]

I think spritesheets are generally used in traditional games since textures have to be a certain size multiple, and then you just choose texture co-ordinates for quads.

I think that textures are always square powers of two (64, 128, 256, 512, 1024 etc) correct me if I'm wrong. Normally you don't have to worry about that but if you're making image heavy app or game you should now that it's better to make sprite that's 512x512 pixels big instead of for example 520x520 because now your gpu uses bigger texture size 1024x1024 and you waste most of the space in it.

The predictive algorithms are in renpy that "look-ahead" to potentially used images are used to load images that are upcoming. If you heard of "branch-prediction" in CPU architecture you'd get a similar idea only with images.

Ren'py looks ahead in the script around 10-100 lines. It check for any graphical resources and loads them ahead of time. If there is a "branch" then it actually looks ahead all the possible branches and loads a little bit of each of them.

That's interesting! I really want to know more. If your prediction is correct then spritesheet seems like better idea than multiple images in for example Turn based RPG battle. Thanks for all answers if anyone knows more how Ren'py works please add reply.

[nyaatrap]

It's not wise to use 2^n texture in ren'py. http://lemmasoft.renai.us/forums//viewt ... xt#p349564

You can know when images are loaded by showing _image_load_log screen. I always show this screen at splashscreen while I'm developing my game.
I use spritesheet on battle animation in my RPG, because it's easily coded when to loads images before they're used. It's for coding efficiency, not for performance.

[Luxliev]

It's not wise to use 2^n texture in ren'py. http://lemmasoft.renai.us/forums//viewt ... xt#p349564

This is really important information I've created new topic so more people could see this. If there are plans to change this I might have problem with my spritesheets.