[HOWTO] Make a NPC with extra features.

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[HOWTO] Make a NPC with extra features.

Post by Archive-Poster »

Seeing that there are a lot of posts in Twilight Suzuka's thread of How To: Make a perfect NPC. I decided to try and make my very own NPC using that tutorial but added extra features.
Some of these are:
Hit animations
Death animations
Idle animations
Bleed/spark effects
NPC voice speaking
And many more!

Before we start this tutorial we better explain what exactly is a NPC and why should we make one before how.

NPC stands for Non-Playable Character. As the name suggests it is simply an entity that is non-playable. We as coders have full control on how they interact and work.
Some examples of what a NPC could do are:
Bystanders that animates. (Pretty cool to make for Soccer Jam)
An item shop owner
Props for your mod. (Making lamp/light posts that could flicker)
Whatever you can think of!

Alright! Lets finally begin on making our very own NPC!

We start by including the necessary libraries to make our NPC

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#include <amxmodx>
#include <amxmisc>
#include <fakemeta>
#include <engine>
#include <hamsandwich> 
A bunch of global variables that our NPC will use.

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//Boolean of when NPC spawned 
new bool: g_NpcSpawn[256]; 
//Boolean to check if NPC is alive or not 
new bool: g_NpcDead[256]; 
//Classname for our NPC 
new const g_NpcClassName[] = "ent_npc"; 
//Constant model for NPC 
new const g_NpcModel[] = "models/barney.mdl"; 

//List of sounds our NPC will emit when damaged 
new const g_NpcSoundPain[][] =  
{ 
    "barney/ba_pain1.wav", 
    "barney/ba_pain2.wav", 
    "barney/ba_pain3.wav" 
} 

//Sounds when killed 
new const g_NpcSoundDeath[][] = 
{ 
    "barney/ba_die1.wav", 
    "barney/ba_die2.wav", 
    "barney/ba_die3.wav" 
} 

//Sounds when we knife our flesh NPC
new const g_NpcSoundKnifeHit[][] = 
{
    "weapons/knife_hit1.wav",
    "weapons/knife_hit2.wav",
    "weapons/knife_hit3.wav",
    "weapons/knife_hit4.wav"
}

new const g_NpcSoundKnifeStab[] = "weapons/knife_stab.wav";

//List of idle animations 
new const NPC_IdleAnimations[] = { 0, 1, 2, 3, 11, 12, 18, 21, 39, 63, 65 };

//Sprites for blood when our NPC is damaged
new spr_blood_drop, spr_blood_spray

//Player cooldown for using our NPC 
new Float: g_Cooldown[32];

//Boolean to check if we knifed our NPC
new bool: g_Hit[32];
Now we have to precache our model and sounds or the game will crash! And also a command to spawn our NPC.

In this section we have to initiate some forwards for our NPC. These are where the extra features are called from.

This is also where we can load our saved configurations.

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public plugin_init()
{
    register_plugin("NPC Plugin", "1.1", "Mazza");
    register_clcmd("say /npc", "ClCmd_NPC");
    
    register_event("HLTV", "Event_NewRound", "a", "1=0", "2=0");
        
    RegisterHam(Ham_TakeDamage, "info_target", "npc_TakeDamage");
    RegisterHam(Ham_Killed, "info_target", "npc_Killed");
    RegisterHam(Ham_Think, "info_target", "npc_Think");
    RegisterHam(Ham_TraceAttack, "info_target", "npc_TraceAttack");
    RegisterHam(Ham_ObjectCaps, "player", "npc_ObjectCaps", 1 );
    
    register_forward(FM_EmitSound, "npc_EmitSound"); 
}

public plugin_precache()
{
    spr_blood_drop = precache_model("sprites/blood.spr")
    spr_blood_spray = precache_model("sprites/bloodspray.spr")
    
    new i;
    for(i = 0 ; i < sizeof g_NpcSoundPain ; i++)
        precache_sound(g_NpcSoundPain[i]);
    for(i = 0 ; i < sizeof g_NpcSoundDeath ; i++)
        precache_sound(g_NpcSoundDeath[i]);

    precache_model(g_NpcModel)
}

public plugin_cfg()
{
    Load_Npc()
} 
When we type "/npc" a menu will display with options of what to do.
Note: I am using the New AMXX Menu System to display the menu

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public ClCmd_NPC(id)
{
    //Create a new menu
    new menu = menu_create("NPC: Main Menu", "Menu_Handler");
    
    //Add some items to the newly created menu
    menu_additem(menu, "Create NPC", "1");
    menu_additem(menu, "Delete NPC", "2");
    menu_additem(menu, "Save current NPC locations", "3");
    menu_additem(menu, "Delete all NPC", "4");
    
    //Let the menu have an 'Exit' option
    menu_setprop(menu, MPROP_EXIT, MEXIT_ALL);
    
    //Display our menu
    menu_display(id, menu);
}

public Menu_Handler(id, menu, item)
{
    //If user chose to exit menu we will destroy our menu
    if(item == MENU_EXIT)
    {
        menu_destroy(menu);
        return PLUGIN_HANDLED;
    }
    
    new info[6], szName[64];
    new access, callback;
    
    menu_item_getinfo(menu, item, access, info, charsmax(info), szName, charsmax(szName), callback);
    
    new key = str_to_num(info);
    
    switch(key)
    {
        case 1:
        {
            //Create our NPC
            Create_Npc(id);
        }
        case 2:
        {
            //Remove our NPC by the users aim
            new iEnt, body, szClassname[32];
            get_user_aiming(id, iEnt, body);
            
            if (is_valid_ent(iEnt)) 
            {
                entity_get_string(iEnt, EV_SZ_classname, szClassname, charsmax(szClassname));
                
                if (equal(szClassname, g_NpcClassName)) 
                {
                    remove_entity(iEnt);
                }
                
            }
        }
        case 3:
        {
            //Save the current locations of all the NPCs
            Save_Npc();
            
            client_print(id, print_chat, "[AMXX] NPC origin saved succesfully");
        }
        case 4:
        {
            //Remove all NPCs from the map
            remove_entity_name(g_NpcClassName);
            
            client_print(id, print_chat, "[AMXX] ALL NPC origin removed");
        }
    }
    
    //Keep the menu displayed when we choose an option
    menu_display(id, menu);
    
    return PLUGIN_HANDLED;
} 
Add some extra features for our NPC.

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public npc_TakeDamage(iEnt, inflictor, attacker, Float:damage, bits)
{
    //Make sure we only catch our NPC by checking the classname
    new className[32];
    entity_get_string(iEnt, EV_SZ_classname, className, charsmax(className))
    
    if(!equali(className, g_NpcClassName))
        return;
        
    //Play a random animation when damanged
    Util_PlayAnimation(iEnt, random_num(13, 17), 1.25);

    //Make our NPC say something when it is damaged
    //NOTE: Interestingly... Our NPC mouth (which is a controller) moves!! That saves us some work!!
    emit_sound(iEnt, CHAN_VOICE, g_NpcSoundPain[random(sizeof g_NpcSoundPain)],  VOL_NORM, ATTN_NORM, 0, PITCH_NORM)
}

public npc_Killed(iEnt)
{
    new className[32];
    entity_get_string(iEnt, EV_SZ_classname, className, charsmax(className))
    
    if(!equali(className, g_NpcClassName))
        return HAM_IGNORED;

    //Player a death animation once our NPC is killed
    Util_PlayAnimation(iEnt, random_num(25, 30))

    //Because our NPC may look like it is laying down. 
    //The bounding box size is still there and it is impossible to change it so we will make the solid of our NPC to nothing
    entity_set_int(iEnt, EV_INT_solid, SOLID_NOT);

    //The voice of the NPC when it is dead
    emit_sound(iEnt, CHAN_VOICE, g_NpcSoundDeath[random(sizeof g_NpcSoundDeath)],  VOL_NORM, ATTN_NORM, 0, PITCH_NORM)

    //Our NPC is dead so it shouldn't take any damage and play any animations
    entity_set_float(iEnt, EV_FL_takedamage, 0.0);
    //Our death boolean should now be true!!
    g_NpcDead[iEnt] = true;
        
    //The most important part of this forward!! We have to block the death forward.
    return HAM_SUPERCEDE
}

public npc_Think(iEnt)
{
    if(!is_valid_ent(iEnt))
        return;
    
    static className[32];
    entity_get_string(iEnt, EV_SZ_classname, className, charsmax(className))
    
    if(!equali(className, g_NpcClassName))
        return;
    
    //We can remove our NPC here if we wanted to but I left this blank as I personally like it when there is a NPC coprse laying around
    if(g_NpcDead[iEnt])
    {
        return;
    }
        
    //Our NPC just spawned
    if(g_NpcSpawn[iEnt])
    {
        static Float: mins[3], Float: maxs[3];
        pev(iEnt, pev_absmin, mins);
        pev(iEnt, pev_absmax, maxs);

        //Draw a box which is the size of the bounding NPC
        message_begin(MSG_BROADCAST, SVC_TEMPENTITY)
        write_byte(TE_BOX)
        engfunc(EngFunc_WriteCoord, mins[0])
        engfunc(EngFunc_WriteCoord, mins[1])
        engfunc(EngFunc_WriteCoord, mins[2])
        engfunc(EngFunc_WriteCoord, maxs[0])
        engfunc(EngFunc_WriteCoord, maxs[1])
        engfunc(EngFunc_WriteCoord, maxs[2])
        write_short(100)
        write_byte(random_num(25, 255))
        write_byte(random_num(25, 255))
        write_byte(random_num(25, 255))
        message_end();
        
        //Our NPC spawn boolean is now set to false
        g_NpcSpawn[iEnt] = false;
    }
    
    //Choose a random idle animation
    Util_PlayAnimation(iEnt, NPC_IdleAnimations[random(sizeof NPC_IdleAnimations)]);

    //Make our NPC think every so often
    entity_set_float(iEnt, EV_FL_nextthink, get_gametime() + random_float(5.0, 10.0));
}

public npc_TraceAttack(iEnt, attacker, Float: damage, Float: direction[3], trace, damageBits)
{
    if(!is_valid_ent(iEnt))
        return;
    
    new className[32];
    entity_get_string(iEnt, EV_SZ_classname, className, charsmax(className))
    
    if(!equali(className, g_NpcClassName))
        return;
        
    //Retrieve the end of the trace
    new Float: end[3]
    get_tr2(trace, TR_vecEndPos, end);
    
    //This message will draw blood sprites at the end of the trace
    message_begin(MSG_BROADCAST,SVC_TEMPENTITY)
    write_byte(TE_BLOODSPRITE)
    engfunc(EngFunc_WriteCoord, end[0])
    engfunc(EngFunc_WriteCoord, end[1])
    engfunc(EngFunc_WriteCoord, end[2])
    write_short(spr_blood_spray)
    write_short(spr_blood_drop)
    write_byte(247) // color index
    write_byte(random_num(1, 5)) // size
    message_end()
}

public npc_ObjectCaps(id)
{
    //Make sure player is alive
    if(!is_user_alive(id))
        return;

    //Check when player presses +USE key
    if(get_user_button(id) & IN_USE)
    {        
        //Check cooldown of player when using our NPC
        static Float: gametime ; gametime = get_gametime();
        if(gametime - 1.0 > g_Cooldown[id])
        {
            //Get the classname of whatever ent we are looking at
            static iTarget, iBody, szAimingEnt[32];
            get_user_aiming(id, iTarget, iBody, 75);
            entity_get_string(iTarget, EV_SZ_classname, szAimingEnt, charsmax(szAimingEnt));
            
            //Make sure our aim is looking at a NPC
            if(equali(szAimingEnt, g_NpcClassName))
            {
                //Do more fancy stuff here such as opening a menu
                //But for this tutorial I will only display a message to prove it works
                client_print(id, print_chat, "Hello");
            }
            
            //Set players cooldown to the current gametime
            g_Cooldown[id] = gametime;
        }
    }
}

public npc_EmitSound(id, channel, sample[], Float:volume, Float:attn, flag, pitch)
{
    //Make sure player is alive
    if(!is_user_connected(id))
        return FMRES_SUPERCEDE;

    //Catch the current button player is pressing
    new iButton = get_user_button(id);
                    
    //If the player knifed the NPC
    if(g_Hit[id])
    {    
        //Catch the string and make sure its a knife 
        if (sample[0] == 'w' && sample[1] == 'e' && sample[8] == 'k' && sample[9] == 'n')
        {
            //Catch the file of _hitwall1.wav or _slash1.wav/_slash2.wav
            if(sample[17] == 's' || sample[17] == 'w')
            {
                //If player is slashing then play the knife hit sound
                if(iButton & IN_ATTACK)
                {
                    emit_sound(id, CHAN_WEAPON, g_NpcSoundKnifeHit[random(sizeof g_NpcSoundKnifeHit)], volume, attn, flag, pitch);
                }
                //If player is tabbing then play the stab sound
                else if(iButton & IN_ATTACK2)
                {
                    emit_sound(id,CHAN_WEAPON, g_NpcSoundKnifeStab, volume, attn, flag, pitch);
                }

                //Reset our boolean as player is not hitting NPC anymore
                g_Hit[id] = false;
                
                //Block any further sounds to be played
                return FMRES_SUPERCEDE
            }
        }
    }
    
    return FMRES_IGNORED
} 
In the event of a new round. We will reset our NPC properties.

Code: Select all

public Event_NewRound()
{
    new iEnt = -1;
    
    //Scan and find all of the NPC classnames
    while( ( iEnt = find_ent_by_class(iEnt, g_NpcClassName) ) )
    {
        //If we find a NPC which is dead...
        if(g_NpcDead[iEnt])
        {
            //Reset the solid box
            entity_set_int(iEnt, EV_INT_solid, SOLID_BBOX);
            //Make our NPC able to take damage again
            entity_set_float(iEnt, EV_FL_takedamage, 1.0);
            //Make our NPC instanstly think
            entity_set_float(iEnt, EV_FL_nextthink, get_gametime() + 0.01);
            
            //Reset the NPC boolean to false
            g_NpcDead[iEnt] = false;
        }    
        
        //Reset the health of our NPC
        entity_set_float(iEnt, EV_FL_health, 250.0);
    }
} 
The method that actually creates our NPC.

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Create_Npc(id, Float:flOrigin[3]= { 0.0, 0.0, 0.0 }, Float:flAngle[3]= { 0.0, 0.0, 0.0 } )
{
    //Create an entity using type 'info_target'
    new iEnt = create_entity("info_target");
    
    //Set our entity to have a classname so we can filter it out later
    entity_set_string(iEnt, EV_SZ_classname, g_NpcClassName);
        
    //If a player called this function
    if(id)
    {
        //Retrieve the player's origin
        entity_get_vector(id, EV_VEC_origin, flOrigin);
        //Set the origin of the NPC to the current players location
        entity_set_origin(iEnt, flOrigin);
        //Increase the Z-Axis by 80 and set our player to that location so they won't be stuck
        flOrigin[2] += 80.0;
        entity_set_origin(id, flOrigin);
        
        //Retrieve the player's  angle
        entity_get_vector(id, EV_VEC_angles, flAngle);
        //Make sure the pitch is zeroed out
        flAngle[0] = 0.0;
        //Set our NPC angle based on the player's angle
        entity_set_vector(iEnt, EV_VEC_angles, flAngle);
    }
    //If we are reading from a file
    else 
    {
        //Set the origin and angle based on the values of the parameters
        entity_set_origin(iEnt, flOrigin);
        entity_set_vector(iEnt, EV_VEC_angles, flAngle);
    }

    //Set our NPC to take damange and how much health it has
    entity_set_float(iEnt, EV_FL_takedamage, 1.0);
    entity_set_float(iEnt, EV_FL_health, 250.0);

    //Set a model for our NPC
    entity_set_model(iEnt, g_NpcModel);
    //Set a movetype for our NPC
    entity_set_int(iEnt, EV_INT_movetype, MOVETYPE_PUSHSTEP);
    //Set a solid for our NPC
    entity_set_int(iEnt, EV_INT_solid, SOLID_BBOX);
    
    
    //Create a bounding box for oru NPC
    new Float: mins[3] = {-12.0, -12.0, 0.0 }
    new Float: maxs[3] = { 12.0, 12.0, 75.0 }

    entity_set_size(iEnt, mins, maxs);
    
    //Controllers for our NPC. First controller is head. Set it so it looks infront of itself
    entity_set_byte(iEnt,EV_BYTE_controller1,125);
    // entity_set_byte(ent,EV_BYTE_controller2,125);
    // entity_set_byte(ent,EV_BYTE_controller3,125);
    // entity_set_byte(ent,EV_BYTE_controller4,125);
    
    //Drop our NPC to the floor
    drop_to_floor(iEnt);
    
    // set_rendering( ent, kRenderFxDistort, 0, 0, 0, kRenderTransAdd, 127 );
    
    //We just spawned our NPC so it should not be dead
    g_NpcSpawn[iEnt] = true;
    g_NpcDead[iEnt] = false;
    
    //Make it instantly think
    entity_set_float(iEnt, EV_FL_nextthink, get_gametime() + 0.01)
} 
The methods which load and save the locations of our NPC.

Code: Select all

Load_Npc()
{
    //Get the correct filepath and mapname
    new szConfigDir[256], szFile[256], szNpcDir[256];
    
    get_configsdir(szConfigDir, charsmax(szConfigDir));
    
    new szMapName[32];
    get_mapname(szMapName, charsmax(szMapName));
    
    formatex(szNpcDir, charsmax(szNpcDir),"%s/NPC", szConfigDir);
    formatex(szFile, charsmax(szFile),  "%s/%s.cfg", szNpcDir, szMapName);
        
    //If the filepath does not exist then we will make one
    if(!dir_exists(szNpcDir))
    {
        mkdir(szNpcDir);
    }
    
    //If the map config file does not exist we will make one
    if(!file_exists(szFile))
    {
        write_file(szFile, "");
    }
    
    //Variables to store when reading our file
    new szFileOrigin[3][32]
    new sOrigin[128], sAngle[128];
    new Float:fOrigin[3], Float:fAngles[3];
    new iLine, iLength, sBuffer[256];
    
    //When we are reading our file...
    while(read_file(szFile, iLine++, sBuffer, charsmax(sBuffer), iLength))
    {
        //Move to next line if the line is commented
        if((sBuffer[0]== ';') || !iLength)
            continue;
        
        //Split our line so we have origin and angle. The split is the vertical bar character
        strtok(sBuffer, sOrigin, charsmax(sOrigin), sAngle, charsmax(sAngle), '|', 0);
                
        //Store the X, Y and Z axis to our variables made earlier
        parse(sOrigin, szFileOrigin[0], charsmax(szFileOrigin[]), szFileOrigin[1], charsmax(szFileOrigin[]), szFileOrigin[2], charsmax(szFileOrigin[]));
        
        fOrigin[0] = str_to_float(szFileOrigin[0]);
        fOrigin[1] = str_to_float(szFileOrigin[1]);
        fOrigin[2] = str_to_float(szFileOrigin[2]);
                
        //Store the yawn angle
        fAngles[1] = str_to_float(sAngle[1]);
        
        //Create our NPC
        Create_Npc(0, fOrigin, fAngles)
        
        //Keep reading the file until the end
    }
}

Save_Npc()
{
    //Variables
    new szConfigsDir[256], szFile[256], szNpcDir[256];
    
    //Get the configs directory.
    get_configsdir(szConfigsDir, charsmax(szConfigsDir));
    
    //Get the current map name
    new szMapName[32];
    get_mapname(szMapName, charsmax(szMapName));
    
    //Format 'szNpcDir' to ../configs/NPC
    formatex(szNpcDir, charsmax(szNpcDir),"%s/NPC", szConfigsDir);
    //Format 'szFile to ../configs/NPC/mapname.cfg
    formatex(szFile, charsmax(szFile), "%s/%s.cfg", szNpcDir, szMapName);
        
    //If there is already a .cfg for the current map. Delete it
    if(file_exists(szFile))
        delete_file(szFile);
    
    //Variables
    new iEnt = -1, Float:fEntOrigin[3], Float:fEntAngles[3];
    new sBuffer[256];
    
    //Scan and find all of my custom ents
    while( ( iEnt = find_ent_by_class(iEnt, g_NpcClassName) ) )
    {
        //Get the entities' origin and angle
        entity_get_vector(iEnt, EV_VEC_origin, fEntOrigin);
        entity_get_vector(iEnt, EV_VEC_angles, fEntAngles);
        
        //Format the line of one custom ent.
        formatex(sBuffer, charsmax(sBuffer), "%d %d %d | %d", floatround(fEntOrigin[0]), floatround(fEntOrigin[1]), floatround(fEntOrigin[2]), floatround(fEntAngles[1]));
        
        //Finally write to the mapname.cfg file and move on to the next line
        write_file(szFile, sBuffer, -1);
        
        //We are currentlying looping to find all custom ents on the map. If found another ent. Do the above till there is none.
    }
    
} 
Miscellaneous method for setting animations for our NPC.

Code: Select all

stock Util_PlayAnimation(index, sequence, Float: framerate = 1.0)
{
    entity_set_float(index, EV_FL_animtime, get_gametime());
    entity_set_float(index, EV_FL_framerate,  framerate);
    entity_set_float(index, EV_FL_frame, 0.0);
    entity_set_int(index, EV_INT_sequence, sequence);
} 
This is my first tutorial on these forums so any feedback is welcome.

Post any questions or comments about this tutorial and I'll do my best to answer them.

Once again, thanks for checking this tutorial out!!
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