How To Make A Displacement Map
Are you new to CGI? You may think that there are so many tools or software are available to do CGI. Here, I am going to tell you about the best process of doing CGI and which tool or software will provide the best output. By keeping this matter into mind, let’s first know about different types of mapping like Bump mapping, Displacement mapping and the procedure of How to Make a Displacement Map as well as other maps. I am going to share a full guideline of these maps that can provide your 3D model extra relief and detail.
What is a Texture Map?
Texture Map or diffuse map is a process by which the details of high frequency is defined, providing color information or creating surface texture on a computer-generated graphics or 3D model. The method was invented by Edwin Catmull in 1974.
You can simply map pixels from a texture to a 3D surface by using this method. This method reduces the number of polygons and lighting calculation that requires to create a real and workable 3D model. Hence, it is a complex process but different types of mapping such as multi-texturing, mipmaps, and more complex mappings like height mapping, bump mapping, normal mapping, displacement mapping, reflection mapping, specular mapping, occlusion mapping, and many other types on the technique have become possible by following this Texture Mapping method.
Let’s have a look at the different types of Mapping
The name gives the definition itself, adding color to the surface of a model is the most obvious part for a texture map. This is so simple like adding color to a wood surface or so complex to do a color map for an entire game character.
A color map is an inevitable subject in a production setting. This map is required almost every 3D model which contains a character or environment. Except for this map, there are other two maps have and you can avoid those also while creating a 3D design, those are Specular Map and Bump/Displacement/Normal Map.
Specular Maps or Gloss Maps shows to the software which area of a model will be shiny or glossy and also helping to identify the magnitude of the glossiness. Do you know how the name Specular Maps came? If you put a plastic or a ceramic or a metal into a strong light source, you will get the shiny surface of those particles and that shiny area will show you a strong specular highlight. If you’re confused about specular highlights, look for the white reflection on the rim of your coffee mug. Another simple example of specular reflection is the tiny white glimmer in our eyes, just above the pupil.
Specular Maps cannot be avoided while developing a game. It provides shiny looks to multiple materials used in a game. Even, different levels of glossiness required between the character’s skin, metal belt buckle, and clothing material.
Bump, Displacement or Normal Map
A bump map is a little bit complex than the earlier example. There are several bumps or depressions have in a model or design, bump maps help to show a more realistic indication of those bumps or depressions.
Let’s consider a brick wall, for example, you can map a brick wall on a flat polygon plane but chances are there of not looking convincing after the final stage. It happens because a flat plane will never show the same way a brick wall would, as the brick wall has cracks and coarseness.
To make the brick wall real, bump maps can add the coarse, grainy surface of bricks, and heighten the illusion that the cracks between bricks are receding in space. It is also true that, if you recreate every brick by hand, you can achieve the same effect. But a bump mapped plane is more computationally efficient. You cannot deny the contribution of bump maps in the modern game industry as games simply could not look the way they do today without bump maps.
It indicates a software which part of a 3D model will be reflective than other areas. But if a models or designs full part become significantly reflective, a reflection map is usually omitted. Reflection maps have a range of grey shades from white to black and with black indicating 0% reflectivity and pure white indicating a 100% reflective surface.
Same as the Reflection map, the only difference is that it shows which part of a 3D model will be transparent. A common use for a transparency map would be a surface that would otherwise be very difficult, or too computationally expensive to duplicate, like a chain-link fence.
Difference Between Displacement, Bump and Normal Map
Do you ever hit a bump on the road to mastering textures for your 3D assets? This question is not to let you feel bad. Many programmers are confused when they enter into Bump, Displacement and Normal map world. Thinking that, these three mapping processes are all similar, is not it right? The answer is “sort of”. Each of these mapping processes adds additional resolution or details on the surface of a 3D model or design. Some of these details are real, some are artificial. Now, I am going to let you give a deep dive into the ocean of designs about what each map does and what they don’t. You’ll also have a better grasp of the strengths and weaknesses of each type of map.
To do a bump map, you need to be familiar with computer graphics. A bump map creates an illusion of depth and texture on a 3D model or design. By using lighting tricks and grayscale method, textures are created.
A bump map is an older type of map. It is very important to let you know that, the details create by the bump map are fake. You may be wondered by hearing the word “fake”. It means, in the bump map process, no additional resolution exists. A bump map is limited to 8-bits greyscale image which has only 256 different colors of black, grey and white. These values in a bump map are used to tell the 3D software has two things. Up or down. When values in a bump map are near to 50% gray, there is little to no detail that comes through on the surface. When values get brighter, working their way to white, details appear to pull out of the surface. To contrast that, when values get darker and closer to black, they appear to be pushing into the surface. To create a 3D model of tiny objects, bump maps are perfect such as pores or wrinkles on the skin. Hence, you can create these tiny objects using a 2D application like Photoshop considering you are just using grayscale values.
Bump maps break easily if it is presented from the wrong angle. As it creates fake details as well as no appropriate resolution, the units of the designs that the bump map is applied to will always be unaffected by the map.
Normal Maps are the new and better version of Bump Maps. Yet, the details and resolution created by Normal Maps are also fake and even it does not add any additional resolution to the 3D model or designs. Overall, a normal map creates the same illusion of depth details on a 3D model like a bump map but it does it differently than a bump map. As it is already discussed above, a bump map uses grayscale values to show either up or down information. On the other hand, a normal map uses RGB information that directly correlated with the X, Y and Z axis in 3D space. You can know about the exact direction of the surface normals are oriented in for every polygon by following RGB information of a 3D application. The orientation of the surface normals, often just referred to as normals, tell the 3D application how the polygon should be shaded. There are two types of normal maps and each of them will show you different look in 2D space. The most popularly used normal map is the Tangent space normal map and it is a mixture of purple and blue. These maps work best for meshes that have to deform during the animation. To create a character Tangent Space Normal Map is a perfect choice. For assets that don’t need to deform, oftentimes an Object Space normal map is used. These maps have a rainbow assortment of different colors as well as slightly improved performance over Tangent Space maps.
Keep in mind, Normal maps are very difficult to create or edit in 2D software like Photoshop. Different types of software are available to create normal maps such as Allegorithmic’s b2m, crazy bump, NDO and so on.
Want to add additional details to your 3D model or design? Easily go with displacement maps as it is the king of all maps. These types of maps physically displace (as the name implies) the mesh to which they are applied. For detail to be created based on a displacement map, usually the mesh must be subdivided or tessellated so real geometry is created.
The great benefit of a displacement map is; it can be created from a high-resolution model or you can paint it by hand. Displacement Maps also consists of grayscale values. You can create an 8-bit, 16-bit and 32-bit displacement mapping whereas a 16-bit and 32-bit displacement map will provide you a better experience than an 8-bit displacement map. In comparison to bump or normal maps, a displacement map will also add significant time to your renders. As a result of this additional geometry, it’s hard to beat the results of a displacement map. Since the surface is modified, the silhouette reflects the additional geometry.
Can I use All these Maps Together?
I believe, you already have a few questions in your mind which might be How to Make a displacement map? or Can I use All these Maps Together? Regarding the first question, I will come later. Let me explain the second one
The answer is, Yes, you can use all these three maps together in some cases. It is advisable to plan to use displacement mapping when you are making big changes to the geometry. Then go for the bum or normal maps for the fine detail. Firstly, understand how each map work, strengths, and weaknesses of each map. Thus you can take an efficient decision. Your ultimate goal should be achieving the perfect result that you are looking for.
How Does Bump Map Works?
A bump map is being used for decades and one of the oldest form of image map types. Usually, the bump map adds surface relief to models. Bump maps are not very resource-intensive. A bump map is popular because it provides a wide range of relief work.
The catch with bump maps is that they cannot render corner or edge detail, which makes them faulty in certain factors, for example adding brick detail to a corner edge. Bump maps are by far the easiest type of relief image to manage as they work with practically any surface, no matter the geometry.
What are the Uses of Displacement Map?
Displacement maps, although they can be derived from the same type of image as a bump map as well as are much more powerful than bump maps. They can truly deform geometry up to and including edge detail, making them ideal for a much wider range of uses such as terrain creation and detail modeling. The displacement map is also known for its height map for its large-scale deformation.
Hence, the displace map is not commonly used. Because the displacement map is computationally intensive. They are familiar with high-resolution geometry that makes them less than ideal for some tasks.
Moreover, if an artist understands the bump map and displacement map both, he/she will be able to add detail to the model easily and intuitively than through other image-based methods.
When to Use Bump Map?
At its simplest, bump mapping only changes the surface of a piece of geometry, whereas displacement mapping is changing the geometry. Bump maps are great at adding a lot of low-relief detail on low-polygon objects, so a one-polygon wall could show hundreds of bricks thanks to bump mapping.
While edge details need to be shown, bump maps creates a problem, as bump mapping is not familiar to work with side detail – it only shows the true underlying geometry.
When to Use Displacement Map?
The displacement map is an advanced technique of 3D models. Displacement maps are a hugely powerful technique as they can intuitively allow model detail to be added with a simple greyscale image. A perfect example is when they are used as a simple method of creating height data for a landscape.
As displacement maps (also sometimes known as height maps) are modifying the underlying geometry, they need higher-resolution meshes to work with than bump maps, which can make them slower to work with. But they can produce stunning results.
Bump map and displacement map can be combined and for example, when using displacement maps to add true relief to a landscape, a bump map can be used to add additional noise to the surface.
This takes some of the computational weight away from the displacement map, allowing faster performance for negligible image loss. Understanding the properties of when and where to use bump and displacement maps can radically improve models and scenes.
Height Differences Between Maps
In terms of displaying height, bump map and displacement map displays it differently due to the underlying science. However, this can also be true of the software being used. Displacement maps especially should be double-checked in the final render software when brought in from an external painting program or other render software; there can be differences between how they are displayed, especially with different levels of geometry. Never assume anything until it has been tested for the specific scene or model required.
How to create own bump map and displacement map?
One of the best things about bump and displacement maps is that visually they make sense, with white areas usually denoting the highest areas, black the lowest and 50% grey equalling no change.
This means that while there are applications like Bitmap2Material that can make a good guess at creating relief, it is sometimes better to use a 2D image application. Using a high-pass filter can be an excellent way to get started in creating a relief map that can then be painted into using traditional 2D printing techniques.
How to make a Displacement Map?
You can add a text or graphic to an image by using Photoshop displacement maps. A normal blend mode of a text or graphic on an image will appear quite separate from the photo. Applying text or graphics using Photoshop displacement mapping makes the additional layer look more like it belongs in the image. Now let’s discuss how to quickly make a displacement map
Step 01: Open a Textured Image as the Background
Select an appropriate photo you will use as the background for your text or graphic. Choose a highly contrasted and textured image to get a noticeable effect.
If you are working on How to quickly make a displacement map from an image for the first time, it will be perfect to select an image with good contrast and texture.
The more contrast and texture your image background will be, the effect will be more pronounced of the displacement map. A less contrasted and textured image will not provide you a good displacement map, you will face trouble seeing the effect at all.
Step 02: Convert Image to Black and White
Now open the Channel panel and select each of the channels to locate which one is showing more contrasted. Check out the red, green or blue channel. These channels will provide you a better look at the texture in your image.
For the image, I am using to illustrate this article is the Blue channel.
Based on the style you are looking to create; you can add or decrease the texture in this step. Check the image below, you will see a grungy look, here the level to increase the contrast is manipulated.
Use shortcut key Ctrl+L to get the levels window. Hold and drag the contrast to left and right in towards the center until your contrast level comes at an expected level.
Step 03: Do not forget to save your image as a New Photoshop Document
Make sure, the image should be only 8 bits per channel. Go to the top menu and click on Image > Mode > Grayscale. Then select Image > Mode > 8 Bits/Channel.
As already the image becomes black and white, this black and white image is the basement of your map. Do not forget to save the image as a new.PSD file.
Either Ctrl+Click or right click on the channel you have chosen and select Duplicate Channel. In Destination > Document, select New. Name your new document and click OK.
Remember to keep the new file in a secured and easy to locate are because you need to open this within the next few steps.
Step 04: Add a Gaussian Blur
Now you need to add some blur to give a natural look to your image. Go to the top menu again and click Filter > Blur > Gaussian Blur, the blur radius level should be 1. Hence, the level may vary based on the resolution of the image. Now save your image.
Step 05: Now add Your text or graphic
Return to your main image, turn on all the channels again by clicking RGB in the Channels panel.
Type in the text or drag and drop your graphic and put it in a suitable position where you want it. Make this new layer the color you look for or use black or white.
Step 06: Apply the Displacement Map
It is time to convert your text or graphics to a smart object. Press shortcut key Ctrl + Click or right-clicking the layer in the Layers panel and selecting Convert to Smart Object.
Again go to top menu, click Filter > Distort > Displace. Let the Settings remain in the Default option and confirm OK. A new window will appear where you need to select the grayscale.PSD image that you have just created. Select and Open it.
Your text/graphic will now have the displacement map applied to it. Zoom in to your image and view it at 100 percent. This will permit you to best see the effect of the displacement map on your text or graphic.
Step 07: Do Refining
This is where you can become tricky in terms of the look of your text or graphic. This trick will provide your text/graphic to make it look more the way you want it. Check out the blend mode, if it is selected as Normal, the text or graphic will not look so great.
Lookout with different blend modes until you satisfied and the text or graphic gets an eye-catchy look. Often the Overlay and Soft Light blend modes work well for a more natural look. You can also replace the layer and alter the blend mode and opacity for greater control.
To adjust the color, you can add a solid color. In the Create New Fill or Adjustment Layer in the Layers Panel select Solid Color and choose a color that’s most suitable for your image.
To select the displacement map only, on your text/graphic layer Ctrl + click on the layer’s icon in the Layers Panel.
With the solid color layer designated, press delete. You will now see your text/graphic in the new color. Experiment again with blend mode and opacity to change it satisfactorily.
Adding a Realistic Road Mark
Open your Channels panel and click on each of the red, green and blue channels to see which has the most contrast. In this example, I chose the Blue one. Click and Duplicate this channel.
This brings up another dialog box (see below). Where it says Document, click on the tab and choose New. Name this file Displace road or whatever you want and click OK.
This creates a new document with the layer named Alpha 1. Before you save this document out as a grayscale PSD (Photoshop) file. You need to add some more contrast, go Menu> Image>Adjustments >Levels, then add Gaussian Blur of 9.9 pixels. This will allow the edges of the road marking vector shape to hug the contours of the road, rather than have a jagged edge. Convert this image to Grayscale and save it out as Displace road.psd. Close this document.
Go back to the original document where we are still in the Channels panel and the blue channel is still highlighted. Click on the RGB layer, to bring back the image to color.
In the Layers Panel (I normally have this nested beside the channels panel) click on the square to the left of the layer thumbnail to bring back the visibility of the road vector shape that I had drawn before making the displacement map. See the image below.
With this layer highlighted, go up to Menu>Filter>Distort>Displace. A small dialog box appears. The amount of distortion that you apply will depend on the values that you enter in the Horizontal and Vertical scale boxes. It defaults to 10 in each box. These values represent percentages.
The higher the values the greater the distortion. Experiment to see the desired effect that you want. When you convert your layers to Smart Objects, any adjustments that you make can be done easily and non-destructively. For this image, I chose 55 on the Horizontal scale and 80 for the Vertical one. I wanted more distortion on the road marking so that it would match the worn look of the road.
At this point, your image may look a bit odd, follow the next step to make it look more blended and realistic.
I added Gaussian Blur of 4px to get rid of the ever so slightly pixelated edge on the shape. Double-click anywhere to the right of the layer to bring up the Layer Style box. I changed the Blend Mode to Overlay, reduced Opacity to 77% and Fill to 90%. In the Blend If section, I moved the black slider to 187 on the Underlying Layer.
Note: If you hold down the Alt/Option key when dragging the black or white sliders, this splits the slider arrow into two which makes the blend more smooth.
Different Uses of Photoshop Displacement Maps
Most commonly text and graphics have displacement maps added to them. You can also use other photos.
By using displacement mapping, you can create more realistic looking reflections, package designing, tattoos on people.
In this example, I have a clear cut a photo of a frangipani flower to use as a tattoo on a girl’s arm. Just adding the flower image as a new layer without any changes looks very unnatural, as illustrated in the image above.
Now apply the above-described steps in the same photo and you will get a more realistic result than before. You can see this difference in the image below.
Before starting to do displacement mapping, make a clear plan regarding how the final output will be. You need to know what you are aiming for. Otherwise, it will be difficult for you to reach your goal. Do experiment with different blend modes, layer opacities, and colors. This will help you get a feel for the different alterations you can make to the process.
Tips & Tricks
· Blue is the worst channel to choose if you are making a displacement map where skin tones are involved.
· The green channel usually shows the most contrast.
· Make sure to use Gaussian Blur when generating displacement maps.
· Displacement maps must be saved out as a grayscale.PSD file.
I hope that the above guidelines will help you a lot to understand the ABCD of displacement maps.