Phase 6 done: see-through cores, faint on sacrifice and rebirth; Phase 7 design

Adrian (2026-11-02): the cores should be transparent so the Pokémon
shows; the Pokémon's death sound when a sacrifice is made or a rebirth
ends; then start the next phase (Phase 6 approved).

- Cores drawn as a solid frame around tinted glass, rendered
  translucent, no occlusion (tools/machine_assets.py).
- The shown Pokémon plays Cobblemon's faint animation and its cry
  pitched down (Cobblemon has no death sounds), vanishes after 2 s; a
  reborn Pokémon then shows in its new form. Tests check the new form.
- Phase 7 decisions (every guardian gets area attacks, Groudon for the
  Basalt Furnace, Giratina replaces the Ender Dragon, dying or leaving
  the arena loses) and design in docs/design.md; README status.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

mod/src/main/kotlin/dev/cobblesurvival/machine/MachineBlockEntity.kt

@@ -54,6 +54,8 @@ class MachineBlockEntity(pos: BlockPos, state: BlockState) : BlockEntity(Machine
     internal var confirmBy: UUID? = null
     internal var confirmUntil = 0L
     private var display: PokemonEntity? = null
+    /** No Pokémon shown before this game time (the old one is still fainting). */
+    private var showFrom = 0L
     private var ticks = 0
 
     val def: MachineDefs.Def? get() = MachineDefs.byCore[BuiltInRegistries.BLOCK.getKey(blockState.block)]
@@ -68,7 +70,7 @@ class MachineBlockEntity(pos: BlockPos, state: BlockState) : BlockEntity(Machine
                 giveBack(level, Component.translatableWithFallback("message.cobblesurvival.machine.shell_broke", "The shell of the %s broke.", machineName))
                 return
             }
-            if (display?.isAlive != true) display = MachineDisplay.spawn(level, pokemon, worldPosition, shell!!.chamber, facing())
+            if (display?.isAlive != true && level.gameTime >= showFrom) display = MachineDisplay.spawn(level, pokemon, worldPosition, shell!!.chamber, facing())
         }
         MachineWork.tick(this, level, def)
         receivedThisTick = 0
@@ -184,8 +186,18 @@ class MachineBlockEntity(pos: BlockPos, state: BlockState) : BlockEntity(Machine
         return true
     }
 
-    /** The Pokémon is gone for good (sacrificed). */
-    internal fun consume() = clear()
+    /** The Pokémon is gone for good (sacrificed): the one shown faints. */
+    internal fun consume(level: ServerLevel) {
+        faintDisplay(level)
+        clear()
+    }
+
+    /** The shown Pokémon faints and goes; the next one shows once it's gone (a rebirth's new form). */
+    internal fun faintDisplay(level: ServerLevel) {
+        display?.takeIf { it.isAlive }?.let { MachineDisplay.faint(level, it) }
+        display = null
+        showFrom = level.gameTime + MachineDisplay.FAINT_TICKS
+    }
 
     private fun clear() {
         pokemon = null
@@ -198,8 +210,6 @@ class MachineBlockEntity(pos: BlockPos, state: BlockState) : BlockEntity(Machine
         setChanged()
     }
 
-    internal fun respawnDisplay() = removeDisplay()
-
     private fun removeDisplay() {
         display?.discard()
         display = null

mod/src/main/kotlin/dev/cobblesurvival/machine/MachineDisplay.kt

@@ -8,6 +8,10 @@ import com.cobblemon.mod.common.pokemon.Pokemon
 import com.cobblemon.mod.common.pokemon.properties.UncatchableProperty
 import net.minecraft.core.BlockPos
 import net.minecraft.core.Direction
+import net.minecraft.core.Holder
+import net.minecraft.resources.ResourceLocation
+import net.minecraft.sounds.SoundEvent
+import net.minecraft.sounds.SoundSource
 import net.minecraft.nbt.CompoundTag
 import net.minecraft.server.level.ServerLevel
 import net.minecraft.world.entity.Entity
@@ -15,6 +19,7 @@ import net.neoforged.neoforge.common.NeoForge
 import net.neoforged.neoforge.event.entity.EntityJoinLevelEvent
 import net.neoforged.neoforge.event.entity.player.AttackEntityEvent
 import net.neoforged.neoforge.event.entity.player.PlayerInteractEvent
+import net.neoforged.neoforge.event.tick.ServerTickEvent
 import java.util.UUID
 
 /**
@@ -28,6 +33,12 @@ object MachineDisplay {
     const val TAG = "cobblesurvival_machine"
     /** The chamber is one block; leave a little room. */
     private const val FIT = 0.9f
+    /** A fainting Pokémon's cry is played lower, as in the games. */
+    private const val FAINT_PITCH = 0.6f
+    const val FAINT_TICKS = 40L
+
+    private class Fading(val entity: PokemonEntity, val until: Long)
+    private val fading = ArrayList<Fading>()
 
     fun register() {
         NeoForge.EVENT_BUS.addListener(::onJoin)
@@ -35,6 +46,23 @@ object MachineDisplay {
         NeoForge.EVENT_BUS.addListener<PlayerInteractEvent.EntityInteractSpecific> { if (isDisplay(it.target)) it.isCanceled = true }
         NeoForge.EVENT_BUS.addListener<AttackEntityEvent> { if (isDisplay(it.target)) it.isCanceled = true }
         CobblemonEvents.BATTLE_STARTED_PRE.subscribe(Priority.HIGHEST, ::onBattle)
+        NeoForge.EVENT_BUS.addListener<ServerTickEvent.Post> { event ->
+            if (fading.isEmpty()) return@addListener
+            val now = event.server.overworld().gameTime
+            fading.removeIf { f -> (f.until <= now || f.entity.isRemoved).also { if (it) f.entity.discard() } }
+        }
+    }
+
+    /**
+     * The shown Pokémon dies (a sacrifice, or the old form at the end of a rebirth; Adrian, 2026-11-02): its cry,
+     * pitched down as for a fainting Pokémon, and Cobblemon's faint animation; then it's gone after [FAINT_TICKS].
+     */
+    fun faint(level: ServerLevel, entity: PokemonEntity) {
+        val species = entity.pokemon.species.resourceIdentifier
+        val cry = SoundEvent.createVariableRangeEvent(ResourceLocation.fromNamespaceAndPath(species.namespace, "pokemon.${species.path}.cry"))
+        level.playSeededSound(null, entity.x, entity.y, entity.z, Holder.direct(cry), SoundSource.NEUTRAL, 1f, FAINT_PITCH, level.random.nextLong())
+        entity.playAnimation("faint")
+        fading += Fading(entity, level.gameTime + FAINT_TICKS)
     }
 
     fun isDisplay(entity: Entity?): Boolean = entity is PokemonEntity && entity.pokemon.persistentData.contains(TAG)

mod/src/main/kotlin/dev/cobblesurvival/machine/MachineWork.kt

@@ -163,7 +163,7 @@ object MachineWork {
         val rules = def.altar!!
         val rewards = altarRewards(rules, pokemon)
         if (core.confirmBy == player.uuid && level.gameTime <= core.confirmUntil) {
-            core.consume()
+            core.consume(level)
             rewards.forEach { give(level, core, player, it.copy()) }
             CobbleSurvival.LOGGER.info("{} sacrificed {} (Lv {}) at {}", player.gameProfile.name, pokemon.species.name, pokemon.level, core.blockPos)
             MachineBlockEntity.tell(player, Component.translatableWithFallback("message.cobblesurvival.machine.sacrificed",
@@ -180,10 +180,10 @@ object MachineWork {
     // --- Rebirth Chamber -------------------------------------------------------------------------------------------
 
     private fun rebirth(core: MachineBlockEntity, level: ServerLevel, rules: MachineDefs.RebirthRules, pokemon: Pokemon) {
+        core.faintDisplay(level)
         rebirth(pokemon, rules.perfectIvs)
         core.rebirthAt = 0
         core.reborn = true
-        core.respawnDisplay()
         core.setChanged()
         core.owner?.let { level.server.playerList.getPlayer(it) }?.let {
             MachineBlockEntity.tell(it, Component.translatableWithFallback("message.cobblesurvival.machine.reborn",

mod/src/main/kotlin/dev/cobblesurvival/machine/Machines.kt

@@ -39,7 +39,9 @@ object Machines {
     })
 
     private fun core(name: String, color: MapColor, sound: SoundType): DeferredBlock<MachineBlock> = BLOCKS.registerBlock(
-        name, ::MachineBlock, BlockBehaviour.Properties.of().mapColor(color).strength(3.5f).requiresCorrectToolForDrops().sound(sound),
+        name, ::MachineBlock, BlockBehaviour.Properties.of().mapColor(color).strength(3.5f).requiresCorrectToolForDrops().sound(sound)
+            // See-through, so the Pokémon in the chamber behind the core shows (Adrian, 2026-11-02).
+            .noOcclusion().isViewBlocking { _, _, _ -> false }.isSuffocating { _, _, _ -> false },
     )
 
     fun register(bus: IEventBus) {

mod/src/main/kotlin/dev/cobblesurvival/selftest/MachineTests.kt

@@ -58,8 +58,8 @@ object MachineTests {
         SelfTestCase("heat_core_cooks_with_hoppers", 800, ::heatCore),
         SelfTestCase("dynamo_core_powers_cables", 100, ::dynamo),
         SelfTestCase("synthesis_core_rolls_drops", 100, ::synthesis),
-        SelfTestCase("altar_core_sacrifice_needs_confirmation", 60, ::altar),
-        SelfTestCase("rebirth_core_makes_a_shiny_first_stage", 100, ::rebirth),
+        SelfTestCase("altar_core_sacrifice_needs_confirmation", 120, ::altar),
+        SelfTestCase("rebirth_core_makes_a_shiny_first_stage", 200, ::rebirth),
         SelfTestCase("machine_preview_shows_the_shell", 300, ::preview),
         SelfTestCase("machine_showcase_builds_every_machine", 100, ::showcase),
     )
@@ -348,6 +348,13 @@ object MachineTests {
         s.helper.startSequence()
             .thenExecute { core.rebirthAt = level.gameTime }
             .thenWaitUntil { s.check(core.reborn) { "the rebirth didn't finish" } }
+            .thenWaitUntil {
+                // The old form faints first; then the chamber shows the new one.
+                val shown = displays(level, core.blockPos)
+                s.check(shown.size == 1 && shown.single().pokemon.species.name == "Charmander") {
+                    "after the rebirth the chamber shows ${shown.map { it.pokemon.species.name }}, not one Charmander"
+                }
+            }
             .thenExecute {
                 core.use(player)
                 val back = Cobblemon.storage.getParty(player).firstOrNull { it.uuid == pokemon.uuid }

mod/src/main/resources/assets/cobblesurvival/models/block/altar_core.json

@@ -1,5 +1,6 @@
 {
   "parent": "minecraft:block/orientable",
+  "render_type": "minecraft:translucent",
   "textures": {
     "top": "cobblesurvival:block/altar_core_top",
     "front": "cobblesurvival:block/altar_core_front",

mod/src/main/resources/assets/cobblesurvival/models/block/dynamo_core.json

@@ -1,5 +1,6 @@
 {
   "parent": "minecraft:block/orientable",
+  "render_type": "minecraft:translucent",
   "textures": {
     "top": "cobblesurvival:block/dynamo_core_top",
     "front": "cobblesurvival:block/dynamo_core_front",

mod/src/main/resources/assets/cobblesurvival/models/block/heat_core.json

@@ -1,5 +1,6 @@
 {
   "parent": "minecraft:block/orientable",
+  "render_type": "minecraft:translucent",
   "textures": {
     "top": "cobblesurvival:block/heat_core_top",
     "front": "cobblesurvival:block/heat_core_front",

mod/src/main/resources/assets/cobblesurvival/models/block/rebirth_core.json

@@ -1,5 +1,6 @@
 {
   "parent": "minecraft:block/orientable",
+  "render_type": "minecraft:translucent",
   "textures": {
     "top": "cobblesurvival:block/rebirth_core_top",
     "front": "cobblesurvival:block/rebirth_core_front",

mod/src/main/resources/assets/cobblesurvival/models/block/synthesis_core.json

@@ -1,5 +1,6 @@
 {
   "parent": "minecraft:block/orientable",
+  "render_type": "minecraft:translucent",
   "textures": {
     "top": "cobblesurvival:block/synthesis_core_top",
     "front": "cobblesurvival:block/synthesis_core_front",