Parallax map size.

[KawaiiKid]

So I've heard lots of different opinions on the max size of what a parallax map should be. Some from 50x50 all the way to 150x150 and beyond. For those of you with a lot of parallax experience, what would you say is a safe size for it? I usually have 2 layers, 1 for the top, and one for shadows.

 

[Eliaquim]

Hi!
Well, I think that 150x150 for parallax is too much. In fact, you will found a lot of different opinions about that.
In my android game, a parallax of 90x90 gives me a black screen in an android device with 2gb ram(LG x power).
The size matters, but it also matters the hardware that the game is running. And if your parallax map has a value in the cache that surpasses the cache limit, it will probably give you a black screen(not load the map). That is my experience.
My game has all maps parallax, and with light effects too.

 

[Andar]

It depends on the hardware you want to run the game on.

150x150 tiles would be the maximum for current top-of-the-line computers
50x50 tiles would be the maximum for older computers, ones that are five years old or so.
20x20 tiles would be handable by mobile devices with their hardware limits.

The problem is that for a parallax map to work, its pictures need to be uncompressed in RAM. And what you usually see of a picture is its compressed size, the size it can be reduced to for storage only.
Uncompressed, a parallax map needs several thousand times more RAM than a tile-based map.

Here is a test: save your parallax map as BMP, not as PNG. You can't use it that way, but BMP has no compression. As a result the BMP-filesize will show you how much RAM your picture needs to be used as a map. And you need that for every layer you're using.

 

[pasunna]

there are some trick about seemless tranfering
like draw a map at the connection on other map
so player just notice a little lack but not much
and keep in mind that the bigger of the map
you will lost your self when developing too
when you put like 100 npc in one map

 

[KawaiiKid]

Here is a test: save your parallax map as BMP, not as PNG. You can't use it that way, but BMP has no compression. As a result the BMP-filesize will show you how much RAM your picture needs to be used as a map. And you need that for every layer you're using.

I saved a 40x38 map I have as BMP at 32 bit to see, and it's only 8mb. This is like nothing, why would this be considered demanding? Even a computer back in 2000 could run this easily.

 

[Andar]

I saved a 40x38 map I have as BMP at 32 bit to see, and it's only 8mb. This is like nothing, why would this be considered demanding?

save the same map as png and it is a lot smaller in comparison, and it is that difference that others had problems with in the past. There was once someone who believed that his parallax pictures would only use KBs because the pictures were saved as that to the drive.
And 40x38 is a relative tame map size, as said above older computers have no problems with 50x50. But I wrote that sentence in case you're one of those that try 200x200 parallax maps, and then you get to different numbers.
And 8 MB for a single picture can still be a lot - for example there are quite a number of mobiles out there that only have 1 GB of RAM, and often half of that is already occupied with their own system and background function. Run a browser with a game in the other 512 MB, and using up multiple cases of 8MB for layered pictures becomes detectable.