WEBVTT 00:00.810 --> 00:02.370 So we've mentioned them lots. 00:02.370 --> 00:05.010 And it's time to discuss normal maps. 00:05.010 --> 00:11.110 So welcome to normal maps in this video you will understand that they are a type of bump map. 00:11.280 --> 00:17.730 You'll gain a greater understanding of how normals actually work and also that they contain direction 00:17.730 --> 00:20.640 information and not hide information. 00:20.700 --> 00:25.470 And we will go over the fact that there are three main types. 00:25.500 --> 00:33.230 So first of all hite's Map vs. normal map a height map with a value of evil or zero toll one describes 00:33.240 --> 00:35.980 the particular surface high to any point. 00:36.000 --> 00:43.050 And we can see that can be used to displace our model if necessary and provide some level of control 00:43.080 --> 00:47.170 and even a basic bump mapping can make something look bumpy. 00:47.190 --> 00:53.520 However a normal map is slightly better in the way that it controls the direction of light across a 00:53.520 --> 00:55.500 surface. 00:55.500 --> 00:58.240 Here we have a normal map of the same surface. 00:58.250 --> 01:00.050 Now obviously these are too deep. 01:00.210 --> 01:05.580 And when we work in three dimensions we can have a whole different gamut of colours. 01:05.700 --> 01:10.560 But in this instance we can see that this zigzag repeats itself so we've got the lower half and the 01:10.560 --> 01:11.490 upper half. 01:11.490 --> 01:17.010 And when we look at the normal map for that particular shape that we've got in front of us imagine it 01:17.010 --> 01:19.060 was a profile of a 3D model. 01:19.200 --> 01:24.140 We can see that the normals are identical the first three are identical to the second three. 01:24.210 --> 01:30.250 Now that gives us no indication of height differences between those surfaces. 01:30.330 --> 01:38.430 So Norman so normal maps themselves they contain direction information not hide information. 01:38.430 --> 01:40.240 I'm not going to stop repeating that. 01:40.290 --> 01:46.320 That is important a lot of people get too confused and think that normal maps convey some sort of height 01:46.320 --> 01:46.830 information. 01:46.830 --> 01:55.110 They in fact do not the RG be colour channel values define the direction of a particular normal across 01:55.110 --> 01:56.320 a surface. 01:56.590 --> 02:04.780 An x y z components are also defined with red green and blue Have you ever noticed that the 3D gimbel 02:04.830 --> 02:09.910 in any package that you work with always sticks to these three colours. 02:10.110 --> 02:13.970 There's a not a coincidence that I'm pretty sure. 02:14.910 --> 02:19.930 So let's have a look at the first one and a hop over to my iPad and just draw this out for you. 02:19.950 --> 02:22.440 We're talk about tangent space Normal's. 02:22.650 --> 02:25.830 Okay so let's talk about Normal's in a bit more detail. 02:25.860 --> 02:32.370 If we make ourselves a triangle for the shape that we're all familiar with it will be made up of three 02:32.370 --> 02:34.950 edges and three vertices. 02:35.100 --> 02:39.900 Each one of these vertices has their own normal associated with it. 02:40.050 --> 02:44.320 Now obviously I'm stark in that 2D space when undoing a drawing like this. 02:44.370 --> 02:47.970 But this also applies to a 3-d space. 02:47.970 --> 02:54.360 Now these edges that are joined this particular one here will have a normal that something like this 02:54.990 --> 03:01.530 90 degrees to this particular edge or indeed if we imagine it's face side on that would also apply. 03:01.650 --> 03:07.340 And this particular normal is an average of this normal and this normal here. 03:08.490 --> 03:15.030 Now ordinarily when light comes in the shade controls somewhat how light is bounced off a particular 03:15.030 --> 03:15.770 surface. 03:15.810 --> 03:23.880 But in general if lights were coming in here and hitting this surface we would expect it to bounce off. 03:24.680 --> 03:31.960 At this sort of angle it was a highly specular surface that would be what it looks like and we can take 03:31.960 --> 03:34.750 control of that when we map an image. 03:34.750 --> 03:37.560 Now obviously we need a face to map an image to see. 03:37.570 --> 03:40.360 But in this case we use a 2D representation. 03:40.360 --> 03:42.850 So let me remove those light lines. 03:42.850 --> 03:44.910 So we still have some light coming in here. 03:44.920 --> 03:51.520 But instead we've mapped an image to the surface to tell the surface how to react to light. 03:51.580 --> 03:58.630 So at these three points that we have weak control how light is actually bouncing as if there was more 03:58.630 --> 04:01.160 geometry than there actually is. 04:01.570 --> 04:08.410 So we pretended for instance that the surface looked like this at this point that it looked like this 04:08.470 --> 04:09.540 at that point. 04:09.670 --> 04:17.410 And it looked like well I don't know that at that point and we can do that with a normal map then we 04:17.410 --> 04:20.730 would see that the light would bounce off considerably different. 04:20.740 --> 04:28.530 So at this point it would bounce back off like that here is likely to bounce off like that. 04:28.540 --> 04:30.930 In fact that might be a bit overkill in that case. 04:31.060 --> 04:37.120 And this point here will bounce back off like that and we can see that this gives us a great deal of 04:37.120 --> 04:45.400 control about how light is interacting with our surface itself much more control then a simple height 04:45.430 --> 04:46.090 map. 04:46.090 --> 04:51.970 Now often these two things are used in conjunction with one another in order to make a model look more 04:51.970 --> 04:53.220 realistic. 04:53.680 --> 04:58.350 Okay so let's have a look now at tangent normal maps an example of them. 04:58.340 --> 05:03.240 This leaves over one of the most common ones along with object space. 05:03.250 --> 05:06.940 Normal maps as well so a cover tangent first. 05:06.970 --> 05:13.870 So here we have a view where we can see that smooth shading makes a difference where flat shading is 05:13.870 --> 05:18.880 you can see that on the normal map and where the cube is says hang on a minute. 05:18.880 --> 05:20.750 Why can't we see the cube on the normal map. 05:20.770 --> 05:26.310 And the reason for that is because the top of the cube is the same direction. 05:26.410 --> 05:34.780 It has the same normal direction as the plane itself and therefore it has no direction change and no 05:34.780 --> 05:37.390 colour change on the normal map. 05:37.660 --> 05:43.030 So a normal maps appearance when creating normal maps they are affected by whether or not the meche 05:43.060 --> 05:50.680 object has smooth shading turned on normal direction is very important otherwise the map will end up 05:50.680 --> 05:52.860 useless and you won't be able to use it properly. 05:52.870 --> 05:59.140 So if we take the same scene again but this time inverts the Normal's of all of the objects that we're 05:59.170 --> 06:05.410 mapping we can see that we end up with a much bolder normal map happening. 06:05.410 --> 06:09.690 And that is actually going to be useless for us if we're using tangent space. 06:09.700 --> 06:14.000 Normal maps is not going to look very nice. 06:14.110 --> 06:15.790 Now there are other normal maps. 06:15.790 --> 06:22.330 Now I know at the beginning I said there are three types but there are four I suppose in general and 06:22.330 --> 06:24.270 a couple of them really aren't used. 06:24.280 --> 06:26.790 And two of them are very similar to one another. 06:27.100 --> 06:29.560 So there are three other normal types. 06:29.560 --> 06:32.890 We've got the camera world an object. 06:32.890 --> 06:39.910 These are all reference points for the normal map and they all have their uses and issues as all of 06:39.910 --> 06:42.170 these things do when we've got choice. 06:42.340 --> 06:45.970 So using the camera at normal space that is highly restrictive. 06:45.960 --> 06:52.780 This is the Normal's according to the camera view itself so if you've got a static camera it's going 06:52.780 --> 07:00.790 to be possibly fine to use it in here but you cannot move the view of a scene without breaking the illusion 07:00.790 --> 07:07.180 of detail as the lighting effect will get worse the further you deviate from that particular view point 07:07.390 --> 07:11.030 because it's the Camrose changing how the normals react. 07:12.370 --> 07:14.410 Using the world space. 07:14.470 --> 07:17.320 Now this is also quite restrictive. 07:17.320 --> 07:19.030 Not as much as the camera. 07:19.330 --> 07:25.220 You cannot rotate deform anything made within the world normal space without breaking the lighting illusion 07:25.270 --> 07:30.810 the moment you do that especially if you change the lighting it will break down. 07:31.760 --> 07:34.000 So using the object normal space. 07:34.010 --> 07:42.560 Now this is a more optimized form and is often used in games because it takes less computational power 07:42.800 --> 07:49.130 because there is a one to one mapping to your objects so you can only use it once as it has this one 07:49.130 --> 07:51.260 to one mapping to the object. 07:51.260 --> 07:55.090 So you can't reuse a normal map across multiple items. 07:55.170 --> 08:01.880 That's let's say we've got a brick work type normal map where you could use that over lots and lots 08:01.880 --> 08:02.630 of different models. 08:02.630 --> 08:05.290 However an object normal space. 08:05.330 --> 08:11.660 Well it's got a one to one mapping to the object so unless the another object is either incredibly similar 08:11.990 --> 08:15.290 or the same we cannot use it on anything else. 08:15.290 --> 08:20.810 Now this is also called local or model space as well as object space. 08:20.810 --> 08:27.090 Now it can generate higher quality maps as the normals are replaced not adjusted. 08:27.200 --> 08:29.880 So with a tangential base it is a. 08:29.900 --> 08:37.550 The normals are adjusted whereas with an object they are replaced with more Normal's so slightly better 08:37.550 --> 08:44.030 rendering performance can result from this and it's easier to visualize because if something is facing 08:44.030 --> 08:51.140 down it will have a completely different normal then if it's facing up now with tangent space we often 08:51.140 --> 08:52.020 see that. 08:52.080 --> 08:58.790 If if a Normal is 90 degrees from that particular face pointing up it will be the same colour wherever 08:58.790 --> 09:00.470 it is on the model. 09:00.470 --> 09:02.950 So using the tangent normal space whereas that you. 09:02.970 --> 09:09.140 Well they are great because they are reusable Regardless subscale defamation or etc. of a model so their 09:09.140 --> 09:16.900 great when used with animation for instance it can be difficult to avoid smoothing issues. 09:16.940 --> 09:24.560 They do save memory and bandwidth because we are Count collating but because we count chelating they 09:24.560 --> 09:28.030 have a slight impact on performance. 09:28.100 --> 09:32.800 They can also be tiled and scaled etc. So that's great. 09:32.810 --> 09:39.500 If we want to use a tiny normal map that we've made on one object much like we did with the displacement 09:39.500 --> 09:45.660 map a moment ago where we changed the ground using a normal map that already existed in our scene. 09:45.770 --> 09:47.280 That's a great too. 09:47.370 --> 09:52.010 There was an enormous mazzara displacement mouth but you can see there that we can reuse these things 09:52.010 --> 09:53.400 over and over again. 09:53.570 --> 09:58.970 And that obviously saves us a lot of work if we can reuse something and it's not no too noticeable that 09:58.970 --> 10:00.010 we're reusing it. 10:00.020 --> 10:03.530 Especially when you're working on models of completely different scales. 10:03.530 --> 10:08.840 It's unlikely that you would notice that the same texture was being used across multiple models. 10:09.530 --> 10:12.340 So using normal maps outside a blender. 10:12.380 --> 10:19.790 Now some external programs or engines will interpret your normal maps differently so adjustments may 10:19.790 --> 10:20.930 be required. 10:20.930 --> 10:24.090 That's just a word of caution when you're exporting. 10:24.110 --> 10:26.900 Most are going to be absolutely fine. 10:26.990 --> 10:31.370 However there will be some times where it doesn't quite work how you wanted it to. 10:31.460 --> 10:35.020 In which case we would have to adjust the normal maps accordingly. 10:36.130 --> 10:37.690 Okay so it's Challenge time. 10:37.690 --> 10:41.460 I'd like you to think about which technique would you use. 10:41.500 --> 10:49.390 So looking at the various normal mapping options which ones would you use in your scene and why now 10:49.390 --> 10:51.840 there's a hint here you can use any of them. 10:51.880 --> 10:54.760 So why is the important part. 10:54.790 --> 10:57.700 Share your ideas in the discussions. 10:57.830 --> 11:00.420 Pause video now and give that a go. 11:02.950 --> 11:04.450 OK guys welcome back. 11:04.630 --> 11:06.990 So which technique would I use. 11:07.000 --> 11:09.040 There is no right or wrong here. 11:09.040 --> 11:16.590 As with most things in blender Now I will be using tangent space for the majority of my models. 11:16.720 --> 11:23.980 And the reason for that is I am still prototyping a want to reuse maps where ever possible cross my 11:23.980 --> 11:24.650 model. 11:24.670 --> 11:29.100 I don't want to have to create unique ones every time for every individual model. 11:29.110 --> 11:33.630 Now if I had a unique item that I knew that there was absolutely no chance. 11:33.730 --> 11:36.920 I may also use an object space. 11:36.940 --> 11:39.000 Normal map for instance. 11:39.000 --> 11:44.830 I suppose if I produced a lectern or something like that I may use an object space for that but everything 11:44.830 --> 11:45.250 else. 11:45.250 --> 11:49.900 I think I'm going to end up using tangent space for what did you come up with. 11:49.900 --> 11:52.300 Did you share your ideas in the discussions I hope you did. 11:52.300 --> 11:56.420 I look forward to reading them and I will see you guys in the next lecture.