Boot-up data transferred to Real3D

[Bart]

Thought this deserved a separate thread. I don't think I've found anything particularly interesting yet but I do now recall that some games set model references that appear to point to VROM during the first display frames but which may not be polygon data. There are a couple of spots in Legacy3D.cpp where I even explicitly test for these addresses.

Fighting Vipers 2 performs a very basic set up of culling RAM during the first frame. I will paste the viewport node and culling node it points to here. I print both the integer and float value for each word.

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Viewport:
000000: 00000000   0.000000
000001: 01000000   0.000000
000002: 04800500   0.000000  <-- display list at 0x500
000003: 43fb4fc7   502.623260
000004: 00000000   0.000000
000005: bf64f92e   -0.894427
000006: 3ee4f92e   0.447214
000007: 3f19999a   0.600000
000008: 3fb5fdbb   1.421806
000009: 3feed9e1   1.866024
00000a: 3f000000   0.500000
00000b: 3f000000   0.500000
00000c: 3ea9db1b   0.331750
00000d: 3f718087   0.943367
00000e: 3e8483f4   0.258819
00000f: 3f7746e9   0.965926
000010: 3ea9db1b   0.331750
000011: bf718087   -0.943367
000012: 3e8483f4   0.258819
000013: bf7746e9   -0.965926
000014: 060007bf   0.000000
000015: 00000000   0.000000
000016: 00802000   0.000000
000017: 00800100   0.000000
000018: 00000000   0.000000
000019: 00000000   0.000000
00001a: 00000000   0.000000
00001b: 00000003   0.000000
00001c: 00000000   0.000000
00001d: 00200600   0.000000
00001e: 002007c0   0.000000
00001f: 00000000   0.000000
000020: 00000000   0.000000
000021: 4e6e6b28   1000000000.000000
000022: 00000000   0.000000
000023: 3727c5ac   0.000010
000024: 00004c00   0.000000
000025: 00ffffab   0.000000


Code: Select all

Display list:
000500: 02040000  0.000000 <-- culling node at 0x40000
000501: 00000000  0.000000
...

Culling node:
040000: 80000412   -0.000000
040001: 00000000   0.000000
040002: 00000000   0.000000
040003: 20000000   0.000000
040004: 00000000   0.000000
040005: 00000000   0.000000
040006: 00000000   0.000000
040007: 017fff00   0.000000 <-- VROM model at 0x7fff00 (0x1fffc00 in bytes)
040008: 01000000   0.000000
040009: eab8eab8   -111775389383496413841719296.000000


Code: Select all

Data in VROM:

01fffc00h: 9E 28 FD A3 9E 37 08 3A 18 49 94 02 04 BF 39 08
01fffc10h: 2B 8E 02 99 84 77 81 81 0A 49 FF BF F7 3A 39 6C
01fffc20h: 07 3C 13 6C B7 77 05 08 00 86 F8 78 C7 A7 11 74
01fffc30h: 00 64 0D 63 08 6E 0F D3 B6 20 E7 06 6F 5A 11 AE
01fffc40h: 83 52 92 CC 64 19 FF 08 35 F9 2A 4C 74 69 01 B1
01fffc50h: F6 21 A6 70 F6 B5 EC 7C 80 61 F8 85 6A 05 8E CF
01fffc60h: 67 20 DE 7D CF DF 59 64 64 99 E8 3A 23 4E E3 8C
01fffc70h: 4D 81 27 00 53 4F AB 50 61 75 BD A1 7E 26 80 C7
01fffc80h: 51 A8 2A E0 67 38 0A 28 54 88 90 08 8C BF 1D 28
01fffc90h: DC 28 40 C8 0B D9 89 05 A3 E9 B7 37 56 C2 D1 C4
01fffca0h: 71 C8 DC F3 FA 94 25 82 10 1A D8 04 40 5F 33 68
01fffcb0h: 8D 49 70 68 00 CD A3 6A B1 FA 9B 0C F9 29 44 9F
01fffcc0h: 43 50 AA EB E2 77 4C 41 4A F9 10 D2 2B F6 46 08
01fffcd0h: 84 38 80 A8 24 22 7F 32 15 13 7F 08 28 48 12 1D
01fffce0h: 84 37 E5 6F F3 BC 32 D8 0B 9C 26 14 00 BE 57 4C
01fffcf0h: CE 60 05 30 8C 09 A6 0A 04 84 AD 08 FB 07 58 E8

I have a hard time distinguishing polygon data visually. Does this look like a mesh to you guys?

[Bart]

Right after this, the first texture data is written to the FIFO. It's the 0x80 format and the reason Supermodel was never catching it is that for some reason, I now look at (header>>24) & 0x0F rather than all 8 bits. Maybe 0x80 in the most significant byte is just a flag of some sort. In Fighting Vipers 2, it looks like nonsense: an incrementing 8-bit value (the full 32 bits are not written).

Here, the first word encodes the length and the second normally encodes the texture format plus the size. All fields are 0 except the highest bit:

Code: Select all

  0000: 0000080c
  0004: 80000000
  0008: 00000000
  000c: 00000004
  0010: 00000008
  0014: 0000000c
  0018: 00000010
  001c: 00000014
  0020: 00000018
  0024: 0000001c
  0028: 00000020
  002c: 00000024
  0030: 00000028
  0034: 0000002c
  0038: 00000030
  003c: 00000034
  0040: 00000038
  0044: 0000003c
  0048: 00000040
  004c: 00000044
  0050: 00000048
  0054: 0000004c
  0058: 00000050
  005c: 00000054
  0060: 00000058
  0064: 0000005c
  0068: 00000060
  006c: 00000064
  0070: 00000068
  0074: 0000006c
  0078: 00000070
  007c: 00000074
  0080: 00000078
  0084: 0000007c
  0088: 00000080
  008c: 00000084
  0090: 00000088
  0094: 0000008c
  0098: 00000090
  009c: 00000094
  00a0: 00000098
  00a4: 0000009c
  00a8: 000000a0
  00ac: 000000a4
  00b0: 000000a8
  00b4: 000000ac
  00b8: 000000b0
  00bc: 000000b4
  00c0: 000000b8
  00c4: 000000bc
  00c8: 000000c0
  00cc: 000000c4
  00d0: 000000c8
  00d4: 000000cc
  00d8: 000000d0
  00dc: 000000d4
  00e0: 000000d8
  00e4: 000000dc
  00e8: 000000e0
  00ec: 000000e4
  00f0: 000000e8
  00f4: 000000ec
  00f8: 000000f0
  00fc: 000000f4
  0100: 000000f8
  0104: 000000fc
  0108: 00000000
  010c: 00000004
  0110: 00000008
  0114: 0000000c
  0118: 00000010
  011c: 00000014
  0120: 00000018
  0124: 0000001c
  0128: 00000020
  012c: 00000024
  0130: 00000028
  0134: 0000002c
  0138: 00000030
  013c: 00000034
  0140: 00000038
  0144: 0000003c
  0148: 00000040
  014c: 00000044
  0150: 00000048
  0154: 0000004c
  0158: 00000050
  015c: 00000054
  0160: 00000058
  0164: 0000005c
  0168: 00000060
  016c: 00000064
  0170: 00000068
  0174: 0000006c
  0178: 00000070
  017c: 00000074
  0180: 00000078
  0184: 0000007c
  0188: 00000080
  018c: 00000084
  0190: 00000088
  0194: 0000008c
  0198: 00000090
  019c: 00000094
  01a0: 00000098
  01a4: 0000009c
  01a8: 000000a0
  01ac: 000000a4
  01b0: 000000a8
  01b4: 000000ac
  01b8: 000000b0
  01bc: 000000b4
  01c0: 000000b8
  01c4: 000000bc
  01c8: 000000c0
  01cc: 000000c4
  01d0: 000000c8
  01d4: 000000cc
  01d8: 000000d0
  01dc: 000000d4
  01e0: 000000d8
  01e4: 000000dc
  01e8: 000000e0
  01ec: 000000e4
  01f0: 000000e8
  01f4: 000000ec
  01f8: 000000f0
  01fc: 000000f4
  0200: 000000f8
  0204: 000000fc
  0208: 000000fc
  020c: 000000f8
  0210: 000000f4
  0214: 000000f0
  0218: 000000ec
  021c: 000000e8
  0220: 000000e4
  0224: 000000e0
  0228: 000000dc
  022c: 000000d8
  0230: 000000d4
  0234: 000000d0
  0238: 000000cc
  023c: 000000c8
  0240: 000000c4
  0244: 000000c0
  0248: 000000bc
  024c: 000000b8
  0250: 000000b4
  0254: 000000b0
  0258: 000000ac
  025c: 000000a8
  0260: 000000a4
  0264: 000000a0
  0268: 0000009c
  026c: 00000098
  0270: 00000094
  0274: 00000090
  0278: 0000008c
  027c: 00000088
  0280: 00000084
  0284: 00000080
  0288: 0000007c
  028c: 00000078
  0290: 00000074
  0294: 00000070
  0298: 0000006c
  029c: 00000068
  02a0: 00000064
  02a4: 00000060
  02a8: 0000005c
  02ac: 00000058
  02b0: 00000054
  02b4: 00000050
  02b8: 0000004c
  02bc: 00000048
  02c0: 00000044
  02c4: 00000040
  02c8: 0000003c
  02cc: 00000038
  02d0: 00000034
  02d4: 00000030
  02d8: 0000002c
  02dc: 00000028
  02e0: 00000024
  02e4: 00000020
  02e8: 0000001c
  02ec: 00000018
  02f0: 00000014
  02f4: 00000010
  02f8: 0000000c
  02fc: 00000008
  0300: 00000004
  0304: 00000000
  0308: 000000fc
  030c: 000000f8
  0310: 000000f4
  0314: 000000f0
  0318: 000000ec
  031c: 000000e8
  0320: 000000e4
  0324: 000000e0
  0328: 000000dc
  032c: 000000d8
  0330: 000000d4
  0334: 000000d0
  0338: 000000cc
  033c: 000000c8
  0340: 000000c4
  0344: 000000c0
  0348: 000000bc
  034c: 000000b8
  0350: 000000b4
  0354: 000000b0
  0358: 000000ac
  035c: 000000a8
  0360: 000000a4
  0364: 000000a0
  0368: 0000009c
  036c: 00000098
  0370: 00000094
  0374: 00000090
  0378: 0000008c
  037c: 00000088
  0380: 00000084
  0384: 00000080
  0388: 0000007c
  038c: 00000078
  0390: 00000074
  0394: 00000070
  0398: 0000006c
  039c: 00000068
  03a0: 00000064
  03a4: 00000060
  03a8: 0000005c
  03ac: 00000058
  03b0: 00000054
  03b4: 00000050
  03b8: 0000004c
  03bc: 00000048
  03c0: 00000044
  03c4: 00000040
  03c8: 0000003c
  03cc: 00000038
  03d0: 00000034
  03d4: 00000030
  03d8: 0000002c
  03dc: 00000028
  03e0: 00000024
  03e4: 00000020
  03e8: 0000001c
  03ec: 00000018
  03f0: 00000014
  03f4: 00000010
  03f8: 0000000c
  03fc: 00000008
  0400: 00000004
  0404: 00000000


[Bart]

LA Machineguns writes something slightly more interesting. Note that the high bit is now set for each value and that they no longer always increment by 4. Looks like a calibration curve. Might be instructive to plot it vs. offset to see how much it deviates from linearity. The data appear to be organized as 4 64-entry tables.

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Real3D DMA copy (PC=0000391C, LR=00003968): 0074A780 -> 94000000, 404
  0000: 00000804
  0004: 80000000
  0008: 80000004
  000c: 80000008
  0010: 8000000c
  0014: 80000010
  0018: 80000014
  001c: 80000018
  0020: 8000001c
  0024: 80000020
  0028: 80000024
  002c: 80000028
  0030: 8000002c
  0034: 80000030
  0038: 80000034
  003c: 80000038
  0040: 8000003c
  0044: 80000040
  0048: 80000044
  004c: 80000048
  0050: 8000004c
  0054: 80000050
  0058: 80000055
  005c: 80000059
  0060: 8000005d
  0064: 80000061
  0068: 80000065
  006c: 80000069
  0070: 8000006d
  0074: 80000071
  0078: 80000075
  007c: 80000079
  0080: 8000007d
  0084: 80000081
  0088: 80000085
  008c: 80000089
  0090: 8000008d
  0094: 80000091
  0098: 80000095
  009c: 80000099
  00a0: 8000009d
  00a4: 800000a1
  00a8: 800000a5
  00ac: 800000aa
  00b0: 800000ae
  00b4: 800000b2
  00b8: 800000b6
  00bc: 800000ba
  00c0: 800000be
  00c4: 800000c2
  00c8: 800000c6
  00cc: 800000ca
  00d0: 800000ce
  00d4: 800000d2
  00d8: 800000d6
  00dc: 800000da
  00e0: 800000de
  00e4: 800000e2
  00e8: 800000e6
  00ec: 800000ea
  00f0: 800000ee
  00f4: 800000f2
  00f8: 800000f6
  00fc: 800000fa
  0100: 800000ff
  0104: 80000000
  0108: 80000004
  010c: 80000008
  0110: 8000000c
  0114: 80000010
  0118: 80000014
  011c: 80000018
  0120: 8000001c
  0124: 80000020
  0128: 80000024
  012c: 80000028
  0130: 8000002c
  0134: 80000030
  0138: 80000034
  013c: 80000038
  0140: 8000003c
  0144: 80000040
  0148: 80000044
  014c: 80000048
  0150: 8000004c
  0154: 80000050
  0158: 80000055
  015c: 80000059
  0160: 8000005d
  0164: 80000061
  0168: 80000065
  016c: 80000069
  0170: 8000006d
  0174: 80000071
  0178: 80000075
  017c: 80000079
  0180: 8000007d
  0184: 80000081
  0188: 80000085
  018c: 80000089
  0190: 8000008d
  0194: 80000091
  0198: 80000095
  019c: 80000099
  01a0: 8000009d
  01a4: 800000a1
  01a8: 800000a5
  01ac: 800000aa
  01b0: 800000ae
  01b4: 800000b2
  01b8: 800000b6
  01bc: 800000ba
  01c0: 800000be
  01c4: 800000c2
  01c8: 800000c6
  01cc: 800000ca
  01d0: 800000ce
  01d4: 800000d2
  01d8: 800000d6
  01dc: 800000da
  01e0: 800000de
  01e4: 800000e2
  01e8: 800000e6
  01ec: 800000ea
  01f0: 800000ee
  01f4: 800000f2
  01f8: 800000f6
  01fc: 800000fa
  0200: 800000ff
  0204: 80000000
  0208: 80000004
  020c: 80000008
  0210: 8000000c
  0214: 80000010
  0218: 80000014
  021c: 80000018
  0220: 8000001c
  0224: 80000020
  0228: 80000024
  022c: 80000028
  0230: 8000002c
  0234: 80000030
  0238: 80000034
  023c: 80000038
  0240: 8000003c
  0244: 80000040
  0248: 80000044
  024c: 80000048
  0250: 8000004c
  0254: 80000050
  0258: 80000055
  025c: 80000059
  0260: 8000005d
  0264: 80000061
  0268: 80000065
  026c: 80000069
  0270: 8000006d
  0274: 80000071
  0278: 80000075
  027c: 80000079
  0280: 8000007d
  0284: 80000081
  0288: 80000085
  028c: 80000089
  0290: 8000008d
  0294: 80000091
  0298: 80000095
  029c: 80000099
  02a0: 8000009d
  02a4: 800000a1
  02a8: 800000a5
  02ac: 800000aa
  02b0: 800000ae
  02b4: 800000b2
  02b8: 800000b6
  02bc: 800000ba
  02c0: 800000be
  02c4: 800000c2
  02c8: 800000c6
  02cc: 800000ca
  02d0: 800000ce
  02d4: 800000d2
  02d8: 800000d6
  02dc: 800000da
  02e0: 800000de
  02e4: 800000e2
  02e8: 800000e6
  02ec: 800000ea
  02f0: 800000ee
  02f4: 800000f2
  02f8: 800000f6
  02fc: 800000fa
  0300: 800000ff
  0304: 80000000
  0308: 80000004
  030c: 80000008
  0310: 8000000c
  0314: 80000010
  0318: 80000014
  031c: 80000018
  0320: 8000001c
  0324: 80000020
  0328: 80000024
  032c: 80000028
  0330: 8000002c
  0334: 80000030
  0338: 80000034
  033c: 80000038
  0340: 8000003c
  0344: 80000040
  0348: 80000044
  034c: 80000048
  0350: 8000004c
  0354: 80000050
  0358: 80000055
  035c: 80000059
  0360: 8000005d
  0364: 80000061
  0368: 80000065
  036c: 80000069
  0370: 8000006d
  0374: 80000071
  0378: 80000075
  037c: 80000079
  0380: 8000007d
  0384: 80000081
  0388: 80000085
  038c: 80000089
  0390: 8000008d
  0394: 80000091
  0398: 80000095
  039c: 80000099
  03a0: 8000009d
  03a4: 800000a1
  03a8: 800000a5
  03ac: 800000aa
  03b0: 800000ae
  03b4: 800000b2
  03b8: 800000b6
  03bc: 800000ba
  03c0: 800000be
  03c4: 800000c2
  03c8: 800000c6
  03cc: 800000ca
  03d0: 800000ce
  03d4: 800000d2
  03d8: 800000d6
  03dc: 800000da
  03e0: 800000de
  03e4: 800000e2
  03e8: 800000e6
  03ec: 800000ea
  03f0: 800000ee
  03f4: 800000f2
  03f8: 800000f6
  03fc: 800000fa
  0400: 800000ff


[Ian]

Could be a gamma look up table?
I know the translator map table also writes to texture memory
It allocates a table of 256 entries

[Bart]

256 entries is pretty small. It could easily be hiding under our noses as a normal texture, couldn't it?

Any chance this could be the translator map? I guess I ought to check Daytona 2, which would have a more distinctive set of values if this were really it.

[Ian]

Honestly I've no clue what the translator map is even supposed to do
But as far as I can see it only effects textures anyway

[Bart]

Something I didn't notice initially is that the last of these 4 tables has the values in descending order. Could this explain the color inversion in Daytona USA? Do the addresses line up in any way with the texture color indices + translator map bits? Daytona 2 uploads the exact same values as VON2 and Fighting Vipers 2.

[Ian]

Bart,
Virtua on seems to be changing the light model with different levels. I spent a few mins this evening debugging this thing and i noticed in between levels it writes to

void CReal3D::WriteTAP

Could there be data in here which configs the GPU ?

[Bart]

Can't rule anything out, I suppose. I haven't really followed the lighting model discussions very well but are you guys sure the various differences and exceptions could not be explained by some sort of look-up tables internal to the Real3D being different? It seems highly unlikely that there would be config bits that switch between minor, fixed variations of a lighting model. Being able to modify some sort of internal color table makes more sense but even then, it's exceedingly bizarre that the developers at Sega would request the ability to do so given that the default lighting model already suits their purpose. The whole TAP functionality was probably never intended for anyone outside of Real3D themselves to mess with.

I'll have a look when I get some time this weekend to see what's being written. I don't know how many other games use the TAP after boot-up, so that will be worth investigating as well.

Out of curiosity, are the mis-colored elements in polygon RAM?

[Ian]

No really the whole lighting model has been modified. It's only a minor change but it makes quite a profound difference to the final output colour

It's this in the shaders

// Optional clamping, value is allowed to be negative
if(sunClamp) {
sunFactor = max(sunFactor,0.0);
}

If the value is negative it literally subtracts from the ambient, making the scene darker.