Unlock the POWER of Blender's Constraints

blender is obviously a huge program and because of this there's some really important areas of blender that tend to get completely overlooked one of the best examples of this is probably the constraint system constraints are a way that you can set up a relationship between two different objects in blender now there's all sorts of different relationships that you can have there's child and parent relationships tracking transformational relationships and sometimes relationships can even turn sexual so today I just want to talk about some of my favorite constraints and how I actually use them in real world projects the simplest form of constraint is probably parenting I assume most people are watching this are probably aware of parenting but basically you just select two different objects go contrl P set it to the object and now anything we do to the parent will also happen to the child as well it'll scale and it'll rotate and move around what we've basically done here is we've told the box to ignore all of its World Properties world scale and World location and just base everything on the settings of the monkey all right so this is pretty handy because it means that we can move the child around wherever we want then the parent will follow but unfortunately what it also means is that it's going to copy everything that the parent does which isn't always what we want so if we clear this parenting we go to the constraints tab going add a child of constraint and Target the monkey head but now let's say we want to follow every action that this monkey head does but we want to ignore it if it's moving on the x- axis well we can do that so now it'll follow us on the Y on the Zed but because we've disabled the X it won't follow us on the x-axis and you can do this with scale and location and everything else another handy thing about this is it also has an influence so what you can do is let's say you want a character to pick something up what I do quite often is I'll use a CH of constraint on the object to attach it to let's say a handbone and then you just have to key frame the influence so that the influence turns on when it grabs the object and now it'll carry the object around the scene a while back I made an animation which some of you may have seen it was like a James Bond style car chase action scene and I start off with the shot of these guys uh jumping off the platform with shotguns and firing a few shots and I used a child of constraint to attach the gun to this guy's hand so that it would follow wherever this hand moves and I also used another constraint called a damp track over here which basically just connects the gun to his other hand whether the damp track works if I add two meshes over here let's say we had this Cube we had another Cube and we put a dam track on it targeting this one wherever we move this in the scene it'll basically rotate itself to always align with the other object that it's track to so I've used that over here to make sure that the shotgun is always aligned properly with his hand when it moves and in the end it looked okay it wasn't great but that was mostly because the animation was a bit crummy but the actual constraints themselves worked great now one of the good things about constraints is that they're all named fairly logically and most things do pretty much what you would expect expect them to do for instance if I apply a follow path constraint and I Target this curve I can change the offset value and it will now move along the curve it will follow the path I can also press follow curve because at the moment you can see it's just facing us the entire time if I press follow curve it will now actually change its rotation to match the curve as it moves along the path now you can key frame this offset or you can use the animate path which will basically do it for you but this is obviously a great tool if you're doing anything like roller coasters or airplanes or Vehicles spaceships anything that you want flying through space but you want to be able to control exactly where it's going to move the various constraints for putting limits on objects can be really useful too this is the scene that I made for my interior masterclass course don't worry I'm not going to plug it right now other than to say you know it's a good course maybe you should buy it but uh yeah this is the same that we made from my interior masterclass course and I have a door stopper down here somewhere over there so what I did is I put a limit rotation constraint on the door which does exactly what you would expect it to do it basically just means that you cannot open this door further than when it should be open or closed uh there's also limit rotation and limit scale once again they basically do exactly what you would expect them to do they're just really handy ways to make sure that you don't accidentally break things when you're working on animations and stuff one constraint that definitely doesn't get enough attention and can be really useful is the shrink wrap constraint if you've used the shrink wrap modifier before you might think you know how this works but not exactly because what it basically does is it just constrains an object so it always has to be on the surface of the target so for instance I've put the modifier on this painting over here and the origin is at the back of the frame then I've targeted the wall so now if I press G I can move this around and I know that this is always going to exactly against the wall now if we move it to another part of the wall you see that we do have a problem here and that it it doesn't align properly it isn't changing its rotation to match the wall so all we need to do is just click align to normal I've got this set to The Zed and then we can move this anywhere we want in the scene and we know that it's always going to be lined up exactly with this wall the constraint that I use by far the most in my own work is the transformation constraint this allows ows us to take the movement or transformation of one object and apply it to an entirely different transformation on another object so let's say you wanted to have this Cube moving backwards and forwards and that would affect the rotation on this monkey head well all we have to do here is just Target the cube and then we're going to map from the movement on the xais so I'm going to say - 2 m to 2 m so that's going to be the range of influence basically if it moves 2 m that way or 2 m that way it's going to have an effect and then what we want to do is change the rotation so I'm going to change this to a rotation mapping I want to change the Z axis which is down here and we getting the information from the X I'm going to change this Zed to X so now this Zed is being mapped from the x- axis of this movement and obviously we need to set the amount so I'm going to say the max is 360° to minus 360 now if we move this 2 m it'll do a 360° spin in either way you can see here that at a certain point it just stops it hits 2 m and then the effect stops if you want this to just go on forever and ever you don't know exactly how far you want the effect to go on for all you have to do is click on extrapolate and now doesn't matter how far we move this thing it will always do it but if we move this cube in other directions it won't have any effect effect now obviously you can just then dial this in we can move this let's say we go 180 to 180 now when we move this Cube it'll only move at half the speed only rotate at half the speed so this is an effect that I use all the time like I said in my own works I can show you some examples of where that's came in handy so a while back I was working on a Bioshock sort of fan animation I will get around to fin finishing that soon um been meaning to for a long time but I made this turret gun and basically the way that works is with this wheel over here so what I did is I used one of those constraints we find this over here we have a transformation constraint on here so as this thing turns it automatically spins the wheel as well so you can see that in action over here this was a complete waste of time by the way because no one's ever going to notice this we can see that the wheel is actually spinning whereas if we turn this constraint off it looks like the wheel is now being dragged across the floor another really great example from the same Bioshock movie is this securest door now all of the movement there is being done by a constraint and it's all based off the movement of one empty so if I move this empty up you can see that it starts turning all of these different cogs and once it reaches a certain level I've also got a movement constraint on the door so these things will start to spin first and then the door lifts up and the same thing when it comes down it it's down for a while and then they stop spinning now one final example of where I found this really handy recently is a little side project that I've been doing called Bounce baits that's those little bouncing musical ball animations you sometimes see on the internet now I've been hand animating the last few of these which is obviously a lot of work as it is to get all the timings and things right and just learning how to do sort of bold physics took quite a long time but I didn't want to have to do the rotation of the ball as well but you can't change the rotation of an object based on its own location so the way that I got around this is I just stuck an empty in the middle of the sphere there's a transformation um constraint on this so as this moves left and right it changes the rotation of the sphere and then I've parented this to the sphere itself so as the sphere moves left and right in the scene it's changing the location of the empty which is in turn changing the rotation of the sphere so I've kind of got an object um to affect itself with a constraint without having any sort of weird causality Loop so one final constraint that I want to talk about is something that I've only just recently found a use for and that's the pivot constraint now let's say you're working on a project like this and we have a mirror modifier and some subdiv set up here we can't actually change the origin of this object without messing everything up right if we grab the origin and we move it it's going to change the mirror because the mirror is based on the origin point but what if we want to say move this object to check how it's going to align with another object well what we could do is use this constraint and we can select this empty here now if we rotate this object you can see that it's actually rotating from the middle of the empty it's not using its own origin Point anymore and we're not messing up the origin and the good thing about this is it has an influence as well so we turn this off it'll go back to the way that it was before and you can add multiple ones of these as well so let's say you have an animation where you want an object to Pivot from lots of different points you can key frame the influence on these and you can accomplish that very easily so thanks for watching this video guys I hope you found this useful remember I've got that big update coming to the interior master class that's probably going to be out hopefully on Friday remember if you buy the course now you do actually get all the future updates for free as well so it's not like you miss out on those if you want to pick that up and start watching it today there'll be links in the description remember to hit the like And subscribe button I really hope you found this useful

Channel: DECODED

Views: 6,391

Keywords: tutorial, DECODED, Blender, blender 3d, software, computing, classes, blender for beginners, blender online, free 3d modeling software, open source software, 3d software, vfx, vfx artist, blender constraints

Id: 9XSevlGrjCA

Length: 12min 4sec (724 seconds)

Published: Tue Apr 30 2024