Blender Tutorial - Full Guide to Boid Particles

hello everyone and welcome back to another blender made easy tutorial today we'll be taking a look at void particles boys if you didn't know is an artificial life form developed by craig reynolds in 1986 what it does is simulate the behavior of verts hence the name boyds the boyd's framework is used in a lot of computer graphics to create realistic flocks of birds schools of fish and herds of animals one interesting fact is that in the original game of half-life it was used to create those weird bird-looking creatures near the end of the game now getting back to blender you can actually access this boyd's physics if you go over to the particle system scroll down to the physics tab and change it over to boyd's it might look a little bit complicated at first but once you get a feel for it it's actually not that hard to summarize boyds what they do is they try to avoid collision objects they try to reach their goals and fly away from predators and this is all according to the buoyed brain how it works is with a set of rules the order of the rules is also very important the particles will try to follow the rules in order but sometimes another rule will take precedence for example if you have a predator in your scene the boyd could kind of forget about the flock rule and just run away from it even though it's instructed not to to add a predator you can go over to the boy to brain and underneath this button here you can click on the avoid rule if you select an object in the target menu the particles will actually move away from the predator this also works very well if you use the buoyed force field if you increase the strength of the force field the particles will move away faster from the object now before we get into anything else let's go over to the settings for the movement there are two sections here for air and land these settings are exactly the same for each and they're pretty easy to understand the three check boxes at the top allow you to choose if you want your particles to fly around the scene walk on land or of course climb objects now let's get into the settings the max speed of course is the maximum velocity that the particles can move the min air speed is the minimum speed that the particles must move during a animation this is also relative to the max air speed for example if you have a minimum air speed of 1 and a max air speed of 50 the particles will always move at a speed of 50. whereas if it's set to a value of about 0.1 or so it's going to move around 10 some of the time because that's the minimum speed that it must go you can see here if i play the animation here is the result the max error acceleration determines how fast a particle can change direction and how fast it can gain speed as you can see on screen the max air annular velocity defines how much a boyd can accelerate in order to fulfill a rule we will get into rules later on in this video so you don't really need to worry about this right now personal space you can probably already guess what this does it's the radius around each of the boits this is also a percentage of the particle size landing smoothness deals with collision objects if a particle is headed straight forward the ground this slider will slow it down as it gets closer to the land if this is turned off the particle will slam full force into the collision underneath that we have all the settings for the land max speed acceleration personal space all of those we just talked about except they apply to the land one setting that did change is the land stick force this determines how strong a force field will affect the particles in this example you can see the force field has a strength of three the landstick force is set to three as well you can see the particles don't move but once i bring the land force to a value of 2 they will start to move because the force field is stronger than 2. this also acts a little bit weird because sometimes the particles will still move even if it's set at a higher number so that's basically what it does next up on our list is we're going to talk about fighting voids we can actually have particles fight each other using the boyd's particle system and we're going to be creating that fight with blender right now so you can go ahead and follow along here we have just a basic cube and we're actually going to keep this in our scene we're not going to delete it we're going to move it over to the left side and then go over to the particle system and create a new one over in the physics setting we're going to switch it over to the boyd's physics and then we're going to scroll down to the relations the void brain and then the battle panel we're going to open up all of these so over in the battle panel we have a couple different options here we have health strength aggression accuracy and range and we'll be going through those in just a second but how this works is we need to actually specify a relation then we need to tell in the boyd brain to actually fight with the fight rule right here so we're going to go ahead and delete the separate and the flock and then add in a new rule and go underneath the fight option here you have a fight distance and this is the maximum distance that the boys will actually fight and then the fleet distance is of course how far they will flee now in order to get this to work we need to add in a new relation so i'm going to hit that plus sign and then we need to select a target so of course we're going to need two particle systems i'm going to select my cube right here shift d it and then move it over to the right side we also need to make sure this is a new particle system so scroll up to the top and then click on that to button to create a new particle system so over in at the relations we're going to select our first cube click on the target object and then select the cube underneath the relations you have three options here we have a friend neutral and enemy friend will mean that the particles will work together neutral means that they're not going to get angry at each other not they're not gonna fight they're just neutral and of course the enemy is when they will actually fight each other in this case i want this cube to be the enemy so i'm going to switch it over to enemy just like that we'll select this cube here select the target and it's going to be this cube over here on the left side and this one is going to be enemy of course so now what happens if we restart and play this you can see the particles are going towards each other and they're actually fighting in order to see this a little bit better let's select an object to be the particles for each side i'm going to press shift a add in another cube place it on the left and then i'll press shift a add in an icosphere and place it on the right we'll select our first cube that we created scroll down to the render tab and then select render as halo to render as object and then for the instant object select the cube i'm going to bring up the size so we can see them a little bit better and the number of particles i'm going to bring down to 100 i'm also going to set the lifetime up to 250 just like this and then the end frame i'm going to set to 100 and blender just crashed all right here we are back in our scene i have just recreated it we have the cube over here and then we have another cube with the icosphere as the particles so now each of these have a relation and it's both set to enemy and the void brain is set to fight let's see what happens if we play this you will see that the particles go towards each other and they start to fight on the right side you have the health and the strength the health is just the health of the particles and if it's at a lower number the particles will die a lot quicker because the health is lower let's go ahead and test this out by setting the health down to 0.1 and over in the cubes we're going to set the strength up to let's go with a value of 0.5 now if we restart and play this you'll notice that the particles are actually flying away because they know they're not going to win the battle and they're just going to die because they have a lower health to actually get the icospheres to fight the cubes over on the left you need to set the aggression higher since the aggression is a little bit lower you can see here the boys will fight this times stronger enemy so if this is lower they're just going to flee because they know they're not going to win the fight but if they have a very high aggression let's go with a value of 25 they will actually fight each other you can see they're still flying away so it looks like we need to go higher let's go with a value of 100 and then if we play this you can see the particles are actually fighting each other even though the cubes are much stronger and at a certain point when a lot of the particles die the aggression becomes too low and so the rest of the particles will just flee because they know they're not going to win the battle so let's go ahead and play this one more time and you can see this sort of an effect let's actually change the health to a higher number let's go with two and then we'll change the health over here to a lower number but we'll increase the strength so let's go with a value of two so now this one is a lot stronger but this one has a lot more health so now if we play it you can see they're going to be fighting each other and we can see this sort of an effect we also have an accuracy and a range the accuracy is the accuracy of each attack for the particles the higher you set this to the attacks will actually hit more often and the range is how far the particles can attack at a certain distance so you can see here this is actually kind of cool you can have a battle with the particles and it can create some really interesting results another thing you can do is if you shift d this cube right here we'll go up to the particles and create a new one i'm going to create a new relation and set the target over to this cube underneath and i'm going to set it over to friend so now these cubes are actually going to work together if we select this cube we'll add in another relation select the cube up top and then also set this one over to friend so now if we restart and play it these particle systems are going to work together to try to destroy the cubes over here on the right and at a certain point you can see the cubes will start to fly away because they know they're not going to win that battle so there you go that is how the fighting works in the particle system in the void physics pretty cool and you can create some really interesting results using this method in the miscellaneous tab there are three settings here banking pitch and height banking deals with the rotation of the object in this example the top one is set to a value of two you will see as it rotates around it banks off to the side whereas the one underneath with a value of zero it has no banking and only rotates along the z-axis the top one is very smooth whereas the bottom one doesn't look that smooth at all pitch adds a bit of rotation to the side vector this means that instead of having the particles move all the way around when they turn around they will actually move off to the side and stay kind of below as you can see here i'm not really sure exactly what height does i've tested many different scenarios and it doesn't seem to make a difference so if you know what the setting does let me know in the comments down below the boy brain is where all the magic happens here is where you can set specific rules for the boys to follow you can set multiple rules and the order in which they obey them is with the rule evaluation here there are three options average random and fuzzy average will set all the rules to have the same priority random of course will give a random role to each of the particles the fuzzy evaluation goes from top to bottom the fuzziness is how hard a boyd will try to follow a certain rule 1 means it will stick to it completely and 0 means it won't affect it at all now let's actually talk about the rules that you can add the first one that we have here is the goal rule this will set the particles to follow the object that is selected if there is no object selected then you can use the void force field keep in mind though it's not going to do anything unless the strength is set to a negative value then the particles will go towards that void force field you can also select in the settings to predict the movement of the goal so if your object is moving around it will predict the movement and go towards that goal the avoid rule deals with predators and the void particles will run away from them this works very well with the void force field as well because there is also a fear factor if the fear factor is lower than the strength of the buoyed force field the particles will run if it's higher then the particles will stay where they're at because they're not afraid of the predator avoid collision rule makes it so that the particles will avoid collisions as they get close to one you can either set it to avoid other void particle systems or deflectors and deflectors of course are collision objects in this example there is a goal for the particles to reach in front of that goal is a collision object with no avoid collision it will just go straight into the plane and smack right into it with the deflector's checkbox turned on it will slow down as it reaches the goal and try to move around the collision object the order is also important with the avoid collision below the goal rule right here it won't have much of an effect but once you move it above the particles will slow down even more and try to go around the plane separate will just have the particles separate from each other spreading outwards as you can see here the area around is set by the personal space in the slider up at the top in the movement settings the higher you set this to the more the particles will spread outwards flock will have the voids copy the movement of a neighboring particle if the particle moves another particle will try to follow that direction follow the leader allows you to pick an object for the particles to follow this is very similar to the goal rule the three settings underneath i did a lot of testing and for some reason i could not get them to work properly the distance slider what that is supposed to do is create a distance between the leader to follow for some reason this doesn't really seem to do anything though even if it's at 0 or 100 the line checkbox allows the particles to follow the leader in a line and the cue size is how many particles are allowed to follow the cue size also doesn't seem to make a difference though even though it's set to 0 or 100 so this setting seems to be bugged but i'm not sure if i'm using it correctly average rule gives you an average velocity for all the particles and this is the average based off of the max speed in the movement setting the speed slider sets the percentage the wonder setting right here gives the particles some random velocity in a certain direction the level is kind of the height for the particles with it set to one the particles will not go that high but with it set to zero the particles will move up the z axis as you can see and of course we have the fight option which we already talked about a little bit so we're going to go ahead and skip that one and there you have it folks that is the boyd's physics in the particle system for blender thank you very much for watching this tutorial and this video did take a long time to make so make sure you leave a like and comment down below what you would like to see next if you are feeling generous make sure to click that subscribe button to see more tutorials in the future thanks again for watching and i will see you in the next one

Channel: Blender Made Easy

Views: 32,260

Keywords: blender, tutorial, 3d, blender tutorial, particles, particle system, boid, boids, animation, beginner, easy, blendermadeeasy, blender made easy, full, guide, to, 2.8, 2.9, blender animation, blender animation tutorial, physics

Id: J3TUPYVsxow

Length: 15min 32sec (932 seconds)

Published: Wed Mar 17 2021