Draw ice in the same way is done with water and glass and shade it like water.

overviewer_core/src/iterate.c

@@ -174,7 +174,7 @@ generate_pseudo_data(RenderState *state, unsigned char ancilData) {
             data = (check_adjacent_blocks(state, x, y, z, state->block) ^ 0x0f);
             return data;
         }
-    } else if (state->block == 20) { /* glass */
+    } else if ((state->block == 20) || (state->block == 79)) { /* glass and ice */
         /* an aditional bit for top is added to the 4 bits of check_adjacent_blocks */
         if ((z != 127) && (getArrayByte3D(state->blocks, x, y, z+1) == 20)) {
             data = 0;
@@ -413,10 +413,13 @@ chunk_render(PyObject *self, PyObject *args) {
                     
                     unsigned char ancilData = getArrayByte3D(state.blockdata_expanded, state.x, state.y, state.z);
                     state.block_data = ancilData;
+                    /* block that need pseudo ancildata:
+                     * grass, water, glass, chest, restone wire,
+                     * ice, fence and portal. */
                     if ((state.block ==  2) || (state.block ==  9) || 
                         (state.block == 20) || (state.block == 54) || 
-                        (state.block == 55) || (state.block == 85) || 
+                        (state.block == 55) || (state.block == 79) ||
-                        (state.block == 90)) {
+                        (state.block == 85) || (state.block == 90)) {
                         ancilData = generate_pseudo_data(&state, ancilData);
                         state.block_pdata = ancilData;
                     } else {

overviewer_core/src/rendermode-lighting.c

@@ -293,7 +293,7 @@ rendermode_lighting_draw(void *data, RenderState *state, PyObject *src, PyObject
     self = (RenderModeLighting *)data;
     x = state->x, y = state->y, z = state->z;
     
-    if (state->block == 9) { /* special case for water */
+    if ((state->block == 9) || (state->block == 79)) { /* special case for water and ice */
         /* looks like we need a new case for lighting, there are
          * blocks that are transparent and need per-face shading
          * if the face is drawn. */

overviewer_core/textures.py

@@ -431,7 +431,7 @@ def _build_blockimages():
        #       48  49  50  51  52  53  54  55  56  57  58  59  60  61  62  63
                36, 37, -1, -1, 65, -1, -1, -1, 50, 24, -1, -1, 86, -1, -1, -1,
        #       64  65  66  67  68  69  70  71  72  73  74  75  76  77  78  79
-               -1, -1, -1, -1, -1, -1, -1, -1, -1, 51, 51, -1, -1, -1, 66, 67,
+               -1, -1, -1, -1, -1, -1, -1, -1, -1, 51, 51, -1, -1, -1, 66, -1,
        #       80  81  82  83  84  85  86  87  88  89  90  91
                66, 69, 72, 73, 75, -1,102,103,104,105,-1, 102 # clay?
         ]
@@ -448,7 +448,7 @@ def _build_blockimages():
        #        48  49  50  51  52  53  54  55  56  57  58  59  60  61  62  63
                 36, 37, -1, -1, 65, -1, -1,101, 50, 24, -1, -1, 86, -1, -1, -1,
        #        64  65  66  67  68  69  70  71  72  73  74  75  76  77  78  79
-                -1, -1, -1, -1, -1, -1, -1, -1, -1, 51, 51, -1, -1, -1, 66, 67,
+                -1, -1, -1, -1, -1, -1, -1, -1, -1, 51, 51, -1, -1, -1, 66, -1,
        #        80  81  82  83  84  85  86  87  88  89  90  91
                 66, 70, 72, 73, 74,-1 ,118,103,104,105, -1, 118
         ]
@@ -551,12 +551,14 @@ def generate_special_texture(blockID, data):
         return generate_texture_tuple(img, blockID)
 
 
-    if blockID == 9 or blockID == 20: # spring water, flowing water and waterfall water, AND glass
+    if blockID == 9 or blockID == 20 or blockID == 79: # spring water, flowing water and waterfall water, AND glass, AND ice
-        # water and glass share the way to be rendered
+        # water,glass and ice share the way to be rendered
         if blockID == 9:
             texture = _load_image("water.png")
-        else:
+        elif blockID == 20:
             texture = terrain_images[49]
+        else:
+            texture = terrain_images[67]
         
         if (data & 0b10000) == 16:
             top = texture
@@ -1749,8 +1751,8 @@ def getBiomeData(worlddir, chunkX, chunkY):
 
 special_blocks = set([ 2,  6,  9, 17, 18, 20, 26, 23, 27, 28, 29, 31, 33,
                       34, 35, 43, 44, 50, 51, 53, 54, 55, 58, 59, 61, 62,
-                      63, 64, 65, 66, 67, 68, 71, 75, 76, 85, 86, 90, 91,
+                      63, 64, 65, 66, 67, 68, 71, 75, 76, 79, 85, 86, 90,
-                      92, 93, 94, 96])
+                      91, 92, 93, 94, 96])
 
 # this is a map of special blockIDs to a list of all 
 # possible values for ancillary data that it might have.
@@ -1789,6 +1791,7 @@ special_map[68] = (2,3,4,5) # wall sing, orientation
 special_map[71] = range(16) # iron door, open/close and orientation
 special_map[75] = (1,2,3,4,5) # off redstone torch, orientation
 special_map[76] = (1,2,3,4,5) # on redstone torch, orientation
+special_map[79] = range(32) # ice, used to only render the exterior surface, uses pseudo data
 special_map[85] = range(17) # fences, all the possible combination, uses pseudo data
 special_map[86] = range(5)  # pumpkin, orientation
 special_map[90] = (1,2,4,8) # portal, in 2 orientations, 4 cases, uses pseudo data