pot3d.py

@@ -0,0 +1,139 @@
+# hi this is super hacky and only converts a tiny segment of display lists.
+# it's really just to get a feel for how the formats work.
+# after extracting/decompressing OoT, run this script on object_tsubo.
+# the top of the pot is missing, i know. see the comment above.
+
+import array
+import io
+import struct
+import sys
+
+name = "pot"
+tw, th = 32, 64 # hardcoded texture width and height
+viscale = 256 # inverted scale, this is arbitrary
+v_base = 0x1838 # offset to first G_VTX command
+
+with open(sys.argv[1], "rb") as f:
+    data = f.read()
+
+f = io.BytesIO(data)
+
+# hardcoded for a rga5a1 texture at the start of the file:
+pix = array.array('H', f.read(tw * th * 2))
+pix.byteswap()
+rgbs = []
+for p in pix:
+    r = (p & 0xF800) >> 11
+    g = (p & 0x07C0) >> 6
+    b = (p & 0x003E) >> 1
+    a = p & 1
+    # TODO: round color calculations. or not? i don't imagine the N64 bothers.
+    rgb = (r * 255 // 31, g * 255 // 31, b * 255 // 31)
+    rgbs.append(rgb)
+
+verts = []
+texes = []
+norms = [] # unimplemented
+polys = []
+
+vi = 0 # vertex index to offset by (incremented after each chunk)
+
+f.seek(v_base)
+opcode = ord(f.read(1))
+
+while opcode == 0x01: # G_VTX
+    counts = f.read(3)
+    numv = ((counts[0] & 0xF) << 4) | ((counts[1] & 0xF0) >> 4)
+    vbidx = counts[2] // 2 - numv
+    vaddr = struct.unpack(">i", f.read(4))[0]
+
+    back = f.tell()
+    f.seek(vaddr & 0xFFFFFF)
+
+    for i in range(numv):
+        if 0:
+            # colored vertices
+            vertex = struct.unpack(">hhhHhhBBBB", f.read(16))
+            x, y, z, w, tx, ty, r, g, b, a = vertex
+        else:
+            # lit vertices
+            vertex = struct.unpack(">hhhHhhbbbB", f.read(16))
+            x, y, z, w, tx, ty, n, p, q, a = vertex
+
+        pos = (x / viscale, y / viscale, z / viscale)
+        # FIXME: texture coordinates are slightly off
+        tpos = ((tx / 32 / tw), 1 - (ty / 32 / th))
+        verts.append(pos)
+        texes.append(tpos)
+
+    f.seek(back)
+
+    while 1:
+        opcode = ord(f.read(1))
+        if opcode not in (6, 5):
+            break
+        if opcode == 5:
+            indices = struct.unpack('>bbbbbbb', f.read(7))
+            a0, a1, a2, _, _, _, _ = indices
+            atri = a0 // 2 + 1 + vi, a1 // 2 + 1 + vi, a2 // 2 + 1 + vi
+            polys.append(atri)
+        elif opcode == 6:
+            indices = struct.unpack('>bbbbbbb', f.read(7))
+            a0, a1, a2, _, b0, b1, b2 = indices
+            # TODO: assert all indices are in range(32)
+            atri = a0 // 2 + 1 + vi, a1 // 2 + 1 + vi, a2 // 2 + 1 + vi
+            btri = b0 // 2 + 1 + vi, b1 // 2 + 1 + vi, b2 // 2 + 1 + vi
+            polys.append(atri)
+            polys.append(btri)
+
+    vi = len(verts)
+
+# write the model file
+with open("{}.obj".format(name), "w") as f:
+    fprint = lambda *args, **kwargs: print(*args, file=f, **kwargs)
+
+    fprint("mtllib {}.mtl".format(name))
+
+    fprint("o {}".format(name))
+
+    for vert in verts:
+        fprint("v", *("{:.8f}".format(v) for v in vert))
+
+    for tex in texes:
+        fprint("vt", *("{:.8f}".format(v) for v in tex))
+
+    #fprint("g {}".format(name))
+    fprint("usemtl {}".format(name))
+    fprint("s off")
+
+    for poly in polys:
+        fprint("f", *("{}/{}".format(i, i) for i in poly))
+
+# write the material file
+with open("{}.mtl".format(name), "w") as f:
+    fprint = lambda *args, **kwargs: print(*args, file=f, **kwargs)
+
+    fprint("newmtl {}".format(name))
+    fprint("Ns 0.0")
+    # i don't know what any of these do but they all look terrible
+    fprint("Ka 1.0 1.0 1.0")
+    fprint("Kd 0.8 0.8 0.8")
+    fprint("Ks 0.0 0.0 0.0")
+    fprint("Ke 0.0 0.0 0.0")
+    fprint("d 1.0")
+    fprint("illum 0")
+
+    fprint("map_Kd {}.bmp".format(name))
+    #fprint("map_Ka {}.bmp".format(name))
+
+# write the texture file
+with open("{}.bmp".format(name), "wb") as f:
+    f.write(b'BM')
+    # format: 32-bit BGRA
+    # everything else: sane default
+    f.write(struct.pack("<ihhi", len(rgbs) * 4 + 14, 0, 0, 14 + 40))
+    f.write(struct.pack("<iiihhiiiiii", 40, tw, th, 1, 32, 0, 0, 0, 0, 0, 0))
+    for rgb in reversed(rgbs):
+        r, g, b = rgb
+        a = 0xFF
+        f.write(struct.pack("<BBBB", b, g, r, a))