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trs:npc_behaviour [2017/02/02 14:14] zdimension [Data Structures] |
trs:npc_behaviour [2017/11/17 12:19] (current) stohrendorf |
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| + | {{indexmenu_n>6}} | ||
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| ====== Non-Player Character Behaviour ====== | ====== Non-Player Character Behaviour ====== | ||
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| Despite the existence of //script files//, here is no any scripting for entity behaviour, like in most contemporary games. This hardcoding makes it difficult to port the earlier Tomb Raider scenarios to the engines of the later games, which could be desirable with their improved hardware support. While textures, models, and animations can be ported, behaviour cannot be. | Despite the existence of //script files//, here is no any scripting for entity behaviour, like in most contemporary games. This hardcoding makes it difficult to port the earlier Tomb Raider scenarios to the engines of the later games, which could be desirable with their improved hardware support. While textures, models, and animations can be ported, behaviour cannot be. | ||
| - | However, there is a small change in TR4 and TR5 which indicates that specific entity behaviour can be altered — it’s called //OCB//. It was briefly described in [[opentomb:trs:meshes_models#object-code-bit|this section]]. OCB is a special value defined for each entity instance, based on which entity can switch the way it acts (most prominent examples are flame emitters, which change their size and emit direction based on OCB, and teeth spikes, which change their orientation in space). | + | However, there is a small change in TR4 and TR5 which indicates that specific entity behaviour can be altered — it’s called //OCB//. It was briefly described in [[trs:meshes_models#object-code-bit|this section]]. OCB is a special value defined for each entity instance, based on which entity can switch the way it acts (most prominent examples are flame emitters, which change their size and emit direction based on OCB, and teeth spikes, which change their orientation in space). |
| Sometimes OCB is interpreted as a “packed” field with several values incorporated — like teeth spike OCB contain information about their horizontal and vertical orientation, and also about their “physical” behaviour (stick out constantly, pop-retract in looped manner, or pop-retract just once). | Sometimes OCB is interpreted as a “packed” field with several values incorporated — like teeth spike OCB contain information about their horizontal and vertical orientation, and also about their “physical” behaviour (stick out constantly, pop-retract in looped manner, or pop-retract just once). | ||
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| }; | }; | ||
| </code> | </code> | ||
| - | In ''%%OverlapIndex%%'', the high bit is sometimes set; this occurs in front of swinging doors and the like. That basically means they are unpassable by large enemies, like the T-Rex. | + | The ''%%OverlapIndex%%'' contains a block mask for path finding by enemies in two highest bits: Bit 15 (blockable) and bit 14 (blocked). The first one marks it as unpassable by large enemies, like the [[:items:details:tr1:trex|T-Rex (ID 18)]], the [[:items:details:tr1:mutant|Mutant (ID 20)]] or the [[:items:details:tr1:centaur|Centaur (ID 23)]] and is always set behind doors. The second one marks it unpassable for other enemies and is set for movable blocks (if blockable bit is set), for closed doors and for some flip maps (set at start). |
| === Overlaps === | === Overlaps === | ||
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| ==== AI Data Block in TR4-5 ==== | ==== AI Data Block in TR4-5 ==== | ||
| - | Beginning with TR4, AI objects are //not kept along with other entities//. Instead, they have their own structure, which is basically simplified [[opentomb:trs:meshes_models#tr4_entity|[tr4_entity]]] structure, and moved to separate data block. This seems reasonable, as the only purpose of AI objects is to serve as “waypoints”, and they have neither //collisional// nor //control// code attached to them. | + | Beginning with TR4, AI objects are //not kept along with other entities//. Instead, they have their own structure, which is basically simplified [[trs:meshes_models#tr4_entity|[tr4_entity]]] structure, and moved to separate data block. This seems reasonable, as the only purpose of AI objects is to serve as “waypoints”, and they have neither //collisional// nor //control// code attached to them. |
| The format of AI object structure as follows: | The format of AI object structure as follows: | ||
