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Author Topic: Sprite graPhics and intro screens  (Read 2475 times)

Pikachumanson

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Sprite graPhics and intro screens
« on: November 10, 2012, 02:48:18 pm »
I tried to find the graphics in hex editor using the values i have found in the ppu. But my search was fruitless. Let's say I want to change the title screen by doing tile map editing. Do i need asm to do that?

Jorpho

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Re: Sprite graPhics and intro screens
« Reply #1 on: November 10, 2012, 03:00:36 pm »
I'll assume by your reference to "ppu" that you're referring to an NES game, but I'm not sure why you're looking for graphics using a hex editor.  Why not just say which game you're looking at?  No need to be coy.

Open up the ROM in Tile Molester.  If you can't find the tiles for the title screen, then yes, the graphics are probably compressed (or the title screen is otherwise algorithmically generated) and you will probably need to know assembly language in order to find out how to edit it.
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Pennywise

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Re: Sprite graPhics and intro screens
« Reply #2 on: November 10, 2012, 03:50:38 pm »
I would recommend settling down and providing as much detail as possible to get the best help.

To clarify, ASM is the ability to read and understand the code in a game. Generally it is not required for simple editing in most cases.

Some times you get lucky and the entire tile map for the title screen is stored uncompressed in the ROM. The best way to find this data is to fire up FCEUX and get to the screen in question,  open the nametable viewer and find the PPU address of the tiles you want to edit. You'll then want to open the hex editor in the emulator and view the PPU memory and go to the PPU address you saw in the nametable viewer.

The tilemap data will always be stored uncompressed within the PPU itself, so search for a string of bytes from the PPU in the ROM and see if you get any hits. Chances are you'll find what you're looking for. Now, some games use a simple form of compression called RLE and I've seen it used in title screen data before, but it's quite easy to figure out. A lot of Konami games like to use it. If you're still reading this, you either screwed up somehow or the game is a little more complicated and requires you to set a write breakpoint in PPU to find where the tilemap data comes from.

Pikachumanson

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Re: Sprite graPhics and intro screens
« Reply #3 on: November 16, 2012, 02:22:58 am »
Thanks for your replies Jorpho and Pennywise. You guys were right on the money!