C - Wind Swept Fields. Blender Days of Type. Blender Tutorial

[Music] welcome everyone to another blender days of type today we are looking at wind again but this time we are focusing on fields of long grass or grain type plants now of course no two fields are the same but we know that there are certain aspects that we need to try and emulate in our scene now i tried to come up with a system that is directable one that will enable us to control all those global parameters we need to be able to create a base of any size distribution of plants we need to be able to control the small swaying movements they make in a breeze and how windy it is overall we also need to be able to determine how many individual gusts of wind there are and their strength and we need to be able to dictate when and where all this happens in our scene so let's get started so here we are in blender i've already got a couple of objects in our scene i have an emitter that i've subdivided 30 times and i also have a substitute mesh for our plants that i've colored on every side so that we can see its orientation and rotation so i just want to create a vertex group c select control g assigned to a group and that's it now we are going to be using a particle system there's an issue with geometry nodes at the moment and i'll demonstrate that problem in a moment and if that issue gets fixed in the future then it's just going to be a simple process of swapping out the particle system for a geometry node system but for the moment in blender to use objects in particle systems they need to be orientated the right way needs to be rotated on the x-axis 90 degrees in the negative y direction and then apply that rotation and scale so let's just get that out of the way for the moment and let's add a particle system so first we want here we want to check advanced i will leave the number for the moment we don't need dynamics we do need rotation we want to render that object we'll increase the size 0.5 will do go down to the vertex groups and in density we'll choose that group and back up in rotation just leave everything the same except for phase to one randomness to two and there's our field now just before i go any further i do want to point out that scale matters in this process so this emitter object has been scaled 10 times and in any project that you create you're going to have to work with scale to get the best results that you would need in your scene okay so we've created our basic distribution of plants but now we need to control the small swaying movements that they make in a steady breeze how do we do that well if we select our emitter object and go to the modifiers tab you can see our particle system here we want to add a displace modifier go to the texture settings choose clouds this is fine for the moment depth to one you can adjust these as you see fit this depth actually is important and we'll get back to that clearly that's all too strong so we just go back to the modifiers lower this uh 0.1 maybe 0.2 in this case just to demonstrate it now one thing we can do with that noise texture that's influencing this geometry is we can determine what coordinates to use and in this case you want to choose another object so if we just add an empty move it over here i will call that empty we'll add a keyframe location we'll go to the end of our timeline move it a little bit eye location and that'll do for a start we choose our emitter again we can come back to this panel choose object choose that empty and if we play our animation it's moving quite fast but you can determine how fast this moves by the key frames that are set for this empty or coming back to your textures and increasing this we'll choose one for the time being we come back to the modifiers you'll see that our plants are not responding to this movement at all that's just because of the stacking order so the displacement modifier has to be above the particles and now all of a sudden these plants are now responding to the underlying geometry i'll just slow this down a little bit go to the end of my timeline bring this back a bit high location okay this is very extreme but i just wanted to point something out right now this is very unstable and this is as far as i get with geometry nodes the system glitches the objects rotate around their access wildly and uncontrollably and it's no good for what we want but if we come back to our particle system up the top there's this little checkbox called regrow and if i check that straight away the whole process becomes more stable and begins to react to the underlying geometry the way i need it to there's no glitching there's no popping in and out of particles they're not rotating around their axis they're maintaining their orientation and so at the moment this is a lot more stable which is great so let's just calm this down a little bit come back to our modifiers lower this and now you're starting to see our plants gently moving in a steady breeze that's completely controllable now if you come back to our texture settings you control the speed and severity with this texture and the empty that's controlling it but this depth is interesting where the particles will move quite smoothly if you want or if you want an agitated breeze you simply increase this depth which increases the i guess the the octaves used in this noise texture but the higher you push this the more agitated the particles become that may be what you want and may not be but it's completely controllable by you the artist okay so we have our plants moving to a steady breeze and i'll just stop it there just pay attention to this emitter if we go back to the particle system we have a render tab we also have a viewport display tab we don't want this emitter to be shown in the render and we're only using it in our viewport as a reference so if i turn that off and i'll just add a simple plane scale to 10 add excuse me add a texture or a color to that maybe raise it up about there we don't have the emitter and its movement showing anymore and now for all intents and purposes we have a field on a steady ground that are interacting with a some kind of breeze okay so let's go back and show that emitter again in the viewport and we'll get rid of the ground plane okay so there's the first step in our process but it's limited looks fine if we're on a flat surface but what happens to our particle system if we want hills mounds an undulating surface as you would find in nature of course what happens to our particle system then well it actually breaks and i'll just demonstrate that so if you go into edit mode proportional editing g z the particles are of course emitted along the normal of this underlying emitter and plants don't do that plants grow more vertically even on a hill even on the side of a hill they are going to grow more vertically of course so this doesn't look very natural so how are we going to fix this so if we choose our emitter again go to edit mode select all go to edge mode right click and mark everything as sharp go back to object mode we'll go to our modifiers we need to add two more modifiers one is an edge split and one is smooth now the edge splits we need to uncheck edge angle so that it's just looking for edges that are marked sharp and we marked everything sharp and for this smooth modifier we want to uncheck x and y so it's only smoothing on the z direction and we boost this factor to 2. now again the particles aren't responding to that because the order of the modifier stack is incorrect so we need to lift these above the particle system so edge split first smooth second this is not working at the moment we need to go back to our particle system go to source and tell the particle system to use the modifier stack as you can see now because our underlying emitter is being cut up and modified so that the faces are more directed towards the z direction our plants are now looking more natural so wherever they are on the hillside they're still reacting to the wind but directed more in the z direction and if we want to create that ground underneath then we can simply duplicate the emitter go back to the modifier stack and delete them all go back to your emitter don't show in the viewport and we now have it's lifted above the origin points of these particles and we now have our grasses on a hillside okay let's get rid of that bring our emitter back oh that's in the render excuse me viewport select all and we'll just flatten this out again something like that select all let's go on z direction zero okay so we're back to our flat field our grasses are moving slightly in the breeze we can control how windy it is how agitated the breeze is so our next step is to create those gusts of wind so our gusts of wind are actually created by wind force objects let's add one bring it out r white 90 and you can see this is having some sort of effect but it's not responding as we want yet just back in the particle system i just want to go to the physics tab and just boost this dampening maybe not that much maybe 105 come back to the scale something more like that now let's have a look at this uh force object now if we go into the physics tab we have a few controls here firstly we want this set to point strength can be i will just put it to 10 at the moment everything else you can basically leave the same but we just want to change this power change it to about three and when you do that they now become responsive to this wind object we are not using to go back into the particle system and we're not using dynamics but they are responding to these force objects so maybe two all right so we have our wind force that creates our gust of wind we can duplicate these as many as we want and just bring these up we're actually aiming or the base of these meshes to have the desired effect now we could move all these space them out a little bit and animate all these as we want but i found the best way or rather the problem that i came across is okay what happens when i want to change the parameters i want to massage the scene a little bit to make it work properly i'm not happy with some aspect i want to change maybe the strength or i want to change the power slightly i can't do that globally for all of all of them so we need a way of being able to control these two parameters because i know that i'm going to want to change them but if i get all these set up in their positions then i'm going to have to delete them all change the settings on one then duplicate them around again and so on so i found the best way to do that is just to start from scratch they will let me choose them okay starting from the beginning we have our wind force we want to add two empties we'll choose spheres bring them over to somewhere here i'll duplicate that bring that over let's name them empty strength empty power so we have our ballpark figures already chosen we're happy with that for the moment the best way to control as many of these force objects as we want is to link those two parameters to these empties via drivers so let's do that just right click add a driver this little screen will pop up it's already got variable plus 10 that's good that's what we want we want to choose the object uh empty strength and we want the z location okay go back to the wind object go to power right click add driver same again you want the empty this time empty power z location so now we can go to these two empties and lock everything that we don't need uh to help with that i'll simply create a little area here for the 3d viewport go to side view one we're hitting one on the numpad and now i have these two drivers driving this wind force one more empty that i want is this guy here and i want to parent the wind object to that empty control p when i want to move this wind object i animate this one empty let's go back to frame one add a keyframe location go to the end of my timeline somewhere there for the moment i location okay now i can duplicate these wind force objects they will inherit their the parent of this empty and they'll inherit the drivers for these as well let's try that all right so i have a basic scene set up and if i'm not happy with it i think it's too strong it's bending the plants over too much it's not responding the way i want the placement is okay i can still go here to these drivers and know that this driver is locked to the z location so i just have to press g keep an eye on what's happening here and just move it up and see if i like what's what's happening again if that's too much bring it down just keep adjusting until i'm happy somewhere there let's just add a ground plane in go back to our emitter in the value viewport raise it up a little bit to account for the origin points again we're just adjusting the scene the way we think we want it in fact we can swap out uh if you noticed i've already got a collection up here collection plants let's go down to render instead of object i go collection and the collection i want is that let's increase ambient occlusion and the effect is obviously a little bit too strong but you get my point we now have a system that we can adjust it can look like a breeze if we want it it can look like gusts of wind are moving through the grain fields it can even be animated to make it look like animals are moving through the grain fields it's completely up to the artist it's completely directable you can determine the look and feel of your scene and the end result is completely up to the artist and we're not tied to a simulation system okay so i hope that helped thanks for watching

Channel: icomdesign

Views: 19,857

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Id: PuPYfyeIXko

Length: 28min 52sec (1732 seconds)

Published: Sun Mar 07 2021