Select a free texture slot and create a new texture of type Marble and name it Quartzthin2. From the Basis menu select Improved Perlin. Under the Mapping tab set Size Y to Save the blendfile, incrementing the file name to pebble This material is not designed to be used as a direct pebble-like texture. Its purpose is to act as a mask when we mix the other pebble type created in earlier recipes. The third material created is a mask to use within a material node setup. The idea being that it will combine the two material types by the amount of black, controlling the gray surface material, or white, controlling the quartz material.
Since this material has no surface features, other than color, it's a lot easier to create. This ensures that its light level will not be affected by shadows or scene lighting. In other words, the mask will work across the entire objects surface.
Three textures have been used to create the vein-like strata through the pebble shape. These are all based on the Marble procedural texture type but with varied settings. Apart from the Marble type settings there are two areas that are vital to the way each texture is applied and positioned onto our pebble. In most cases, the Contrast has been set quite high, while the Brightness has been varied to give different results.
This scaling can be used to both alter the rotation of where the marble texture veins will appear, as well as alter the space between the veins. Obviously, if you reduce the scale too much, the texture will appear to become just streaks across the surface and therefore rather unnatural. Because procedural textures are mathematically generated they appear to occupy the whole 3D space. Therefore, because they are mapped to our pebble mesh they look as though they travel right through the surface.
This technique of using scale to rotate a procedural texture is useful in other circumstances and will therefore be used in future recipes.
There are also other techniques that can be used to scale and rotate textures without the inherent distortion that this scaling can sometimes give. These will also be explored in future recipes. You may wonder why we have created this third material when it could have been created with Node textures directly within the node tree.
When creating any texture, it's a good idea to see exactly how it will map to the mesh surface. Creating within its own material means we can just see where the veins will be and how they mix with each other.
It can be very difficult to conceptualize a surface material without constant test renders. It is faster to render a single material than a complex node setup when you are at the development stage. It is a bit like getting your ingredients correct before baking your perfect cake.
We will create a node material made up from the three materials created in the previous recipes. One representing the base gray sandstone texture, another representing the quartz layers, and a third that will act as a mask to mix the final result. To help manage material node creation, it is a good idea to rearrange the interface as shown below.
This gives a large Node editing window with the Material and Texture properties conveniently on the right of the screen. It provides a camera view and an Image editor with the render result. If you don't feel confident about setting this up yourself refer to Chapter 4 , Managing Blender Materials , which includes a simple recipe for creating such a view.
Load u p the pebble Should you have not completed that recipe you can download it from the Packt Publishing website. To create a node material we should have the object selected and ideally start with the main material selected.
In our case, it is the Surface-Color material created at the beginning of the first recipe in this section. With the pebble object selected change the Node type to Material in the Node editor. That's the little material icon next to the material name. This selector is the same as that in the Materials properties panel but more convenient when we are working with nodes.
Finally, select the UseNodes check-box to enable the Node editor. A blank Material node linked to an Output node should be displayed. In the Material node choose the SurfaceColor material created earlier. If you render at this point the pebble would display the SurfaceColor material because that's the only node material being fed to the Output node.
It's time to add our Quartz material to the node tree. Depending on what node is selected, before you added this new node, Blender will attempt to make a link automatically. This may not be what you need. To remove an incorrect link, just drag the link away from the input it may have incorrectly attached to. You can learn all about node editing from the BlenderWiki.
In this Material node, choose the Quartz material created earlier. Link the Color output socket from the SurfaceColor material node to Color1 input, and the Color output socket from the Quartz material node to Color2 input. Change the mix type to Screen. Blender Node editor is incredibly useful in combining materials in all kinds of new ways. It allows multiple materials to be combined on single objects. We have employed a simple mask here to accurately combine totally different materials onto our pebble simulation.
In a sense we have created a new form of stencil to mix different textures controlled by a mask material. The difference with a node material is that the mask is much more flexible than the texture example we used in the individual materials. Of course, that is not the only thing that material nodes can achieve. However, it is a very useful technique simply achieved using three materials and an uncomplicated mixing method. Material nodes in Blender are one of the unique features that make it such a versatile 3D suite.
Nodes can be used to create really detailed and interesting materials, something that is not possible with materials alone. We have used it here to mix two separate materials, using a third to filter the mix result. Later, we will examine more complex examples of node tree set ups. However, it's important to realize that a good node material does not have to be complex to work. You may have noticed that your renders are not quite the same as those illustrated in this book.
That is because I have set up some variations in the lighting and rendering options to produce a better quality render. This is not necessary while you are developing a material solution as it will increase the render times for all test renders.
However, if you would like to know how to duplicate the look of the renders in this chapter there is a recipe included in Chapter 4 , Managing Blender Materials. Chapter 5, Varying environment map reflections to simulate corrosion or wear.
Larger rock materials, for boulders, stone statues, or Stone Age circles, follow many of the principles learned in the previous pebble recipe. The main difference is one of scale and learning to obtain the correct scale for any object is an important step to producing good textures. Although procedural textures can be used to create any scale rock occasionally, we will require photo reference to aid the organic structure that defines many rocks.
We might not have ready access to larger rock formations for either direct observation or taking photo reference. While there are references available on the Internet, their resolution can be too low to use within a material. We will, therefore, also discuss other methods of creating images for larger rock formations.
The approach with these recipes is not to create a finished image but rather explore approaches that can be applied to any larger rock surface. Preparation for this recipe involves creating a simple scene comprising several box-like shapes subdivided a few times and tweaked in mesh edit to vary their shape. A simple plane is created to represent the ground and the two default lights adjusted to cast interesting shadows across the rock surface. Increase or decrease their intensity to obtain the best contrast in your render.
You should be setting the lights up to aid your material creation at this stage rather than for a final render. You can also move the camera for a better angle if you like. Set your mesh to smooth shading and add a sub-surface modifier. To aid the process of shaping the mesh, ensure the Apply modifier to editing cage during Editmode button is selected. A simple sky blend background, from a yellowish white at the horizon to a light blue in the sky, will silhouette the darker rocks against the light background.
This will ensure that the scaling will apply to the mesh, making the mapping of the material and textures consistent. Save this as a blendfile, naming it rock-default. This default scene, with no materials created, can then be used with each of the following rock recipes. Should you wish to use the same mesh as I have used you can download it from the Packt Publishing website. This is a simple scene with no materials created.
However, you will see that Blender will still render the scene, making surfaces visible with specularity together with shadows giving some idea as to the shape of our created mesh.
Blender has a default material that is light gray in color with a small specular setting that makes the surface look like plastic. When creating an animation it can be useful to test render complex scenes without textures applied to speed the process of animation blocking. Once happy with the movement you can go on to create spectacular materials to bring the scene alive.
We will use this Blender scene in each of the following recipes creating those spectacular materials. Rocks on the sea edge are always fascinating.
They are pounded at least twice a day through tides and storms. Life clings to them where it can and, apart from the natural elements that shape its surface, they are textured by birds and other transitory creatures that leave their mark on its surface. You will need to load the rock-default. Or if you have not been able to complete the previous recipe you can download the file from the Packt Publishing website.
Because we will be using this same blendfile for other recipes in this section you are advised to save it immediately after loading, and rename it Sea-Rock Let' add an initial material to our rock mesh.
To do so make sure the object is selected. Set Diffuse color to R to 0. Set the Specular type to Wardiso , with Intensity set to 0. All other settings in the materials panel can stay at their default values.
Switch to the Texture panel and create a new texture of Type Clouds and name it cloud. For the moment we will not use this texture to add any color, bump, or specular changes to our material. We will, however, use it to modify the shape of our rocks via the Modifiers panel. To use this ensure that your mesh has been set to Smooth shading and that you have a Subdivision Surface modifier already in the stack. The settings for this can be quite small at 2 Subdivision levels for View or Render.
Switch to the Modifiers panel and add a new modifier of type Displace. Under Texture , click the checker icon and you should see your cloud texture as a selection. Select it and under Strength set the value to 0. You should immediately see the mesh distort slightly. If it's too much, reduce the Strength value a little more.
Switch back to the Texture panel and deselect the cloud texture just created. The tick mark should be off. We will not be using this texture for any other purpose just yet. We could actually delete it here because that would only disconnect the texture from our material. It still exists because it's now being used by the Distort modifier. In fact, you may have noticed that a number has since appeared to the right of the texture name cloud.
This shows that this texture is being used that number of times. It should be 2, because it's in the modifier and in the Material, even if it's not turned on at the moment. It sounds quite confusing but you don't need to worry about it at this stage. Select the next clear texture slot and click the new button. Select the Clouds texture type and name the texture rock-cracks.
Under the Mapping tab change the Size Z value to 0. In the Geometry select Normal and set to Under Blend , select type Multiply and check the Stencil checkbox. Finally, change the default color to R 0. Time to save your work to ensure you don't lose anything should the unforeseen happen. Name your file Sea-Rock A quick render produces a quite nice rock. Remember, the only thing adding those deep and complex cracks and the green growth streaks is a simple cloud texture.
Textures can be applied to an object in Blender other than via the materials settings. Here we used a texture that we temporarily loaded into a material texture slot and then applied it as a modifier to distort the mesh to give some variety to the surface. To use a texture for such purposes it must exist in the data structure of the blendfile. The easiest way to do this is to load it into a spare texture slot of a material, name it so it can be recognized, then use it with the modifier.
Once that has been done you can 'unlink the datablock', from the material if you want. Alternatively, just leave the texture in the material but turn off its influence. Employing a simple clouds texture to add vertical elongated cracks to our rocky surface is a really easy way to create larger rocks.
Here we employed a scaled cloud texture to add both color and a bump to the surface. Procedural textures like cloud are ideal for this purpose as they are randomly generated just like the natural surface of rocks can be.
However, cracks in large rocks tend to be in a certain direction and by rescaling in the Z axis we give the impression that the cracks are vertical striations. We had to reduce the Z scale to achieve this. Scaling below 1 will actually increase the stretch of a procedural texture. Scaling above 1 will squash the texture in the scaled axis. Water can also play an important part in the surface properties, adding extra specularity and reflection at certain times of the day.
We shall be dealing with water in later chapters, so for these recipes we will assume that the tide is out. We will combine future water exercises with some of these chapter rock recipes later. Chapter 6, Creating realistic large-scale water in Blender 2.
In this recipe we will create a simulation of seaweed, or other living crustacean, that can be found on the sea washed base of rocks on the edge of a beach. We will explore texture nodes in this recipe, using some comprehensive texture node modifiers. You will need to load the blendfile saved at the end of the last recipe. If you have not completed that recipe you can download a pre-created blendfile from the Packt Publishing website.
We can add more to bed our rock into the life rich environment of the seashore. Select a free texture slot, below the last one created, and create a new node texture. Name it NT-Blend-mask and delete the Checker input.
In future, you should know how to add a texture node using this key combination. In its settings select type Easing and ensure it is a Horizontal blend. Now connect it to the Output node. Blends are very useful to help mask parts of a texture. However, we can modify the blend to do much more than just go from black to white.
Use your mouse to modify the curve to look something like in the following screenshot:. Change the default name of the Output node to Vegetation-stencil. Back in the Texture panel let's set the way this texture will be applied to our material.
Below the texture name in the panel you will see that there is a new selector called Output : if you click on this a list of available outputs for that node texture will be shown.
Select Vegetation-stencil. It is possible to set up multiple named outputs that can individually be selected in the Texture panel. Each named output can have multiple nodes to control that output thus making a truly versatile texture tool. Under Influence select Color and set to 0. Select a free texture slot below the NT-Blend-mask texture previously created. This time, rather than creating a new texture select from the list, click on the checker icon by the name and select NT-Blend-mask.
Yes, it's the same texture but we are going to add a new output after further modifying the Blend. You could have just created a new node but sometimes it's quicker to copy one already in the node tree. Modify the curve so that it looks like the following screenshot.
You can create a Viewer node and connect the Blend output socket to the Viewer node. This will enable you to see its output at this stage of the node tree. You can feed its output socket to the Viewer node to see what it looks like. You will see that the Viewer node has been moved to after the Mix node. Feed its output socket to the Viewer node to see how that has altered the Blend. You have three more jobs to do to complete this new output.
Firstly, we will scale it slightly and then invert it, and finally create a new named output that we can use in the material. Set its scale as X to 0. Switch back to the Texture panel, so that we can set the influence of this new modified texture node output. As you can see, it has no visual impact on the material as yet. This node texture output has become an irregular mask for a texture we will create to simulate crustaceans, or seaweed growth on the base of the rocks.
Select the next free texture slot and create a new texture of type Clouds and name it Limpets. Please note that it is not designed to represent limpets per se. It's just a nice shorter name that gives the gist of what we are trying to simulate.
This recipe has used the Texture node system to demonstrate the extraordinary capabilities now offered in the Blender 3D suite. Node textures enable any procedural or image texture to be filtered and modified in many exciting ways. Here we used it to create some quite complex stencils or masks. These were then used to mix and combine textures in quite subtle ways. However, there are only three textures used to produce this effect. A texture node was created with two outputs, both acting as masks or stencils for the last texture.
Although it is possible to create almost any texture variation with a node texture, we have actually covered those areas that are most frequently used. These include mixing methods, levels adjustment, and distortions. A node texture can be used in both node and standalone materials. They are not great but not bad either.
Sometimes it is here I find exactly what I am looking for, so I tend to keep this site in mind. Well worth to be a patron for. I am fairly sure the website is built on the same framework as Texturehaven. The framework was originally released by Greg Zaal who created HDRIHaven and the sites structure looks very similar and the search feature is about as bad as it is on the haven sites.
However, browsing the library is a good experience. The download is through Google Drive, and I am not a big fan. It gives the user a different experience depending on if you are logged into Google or not and if you want to download a set of textures as a ZIP package, the process is pretty slow. Website: 3dtextures. This site takes a similar approach to sharetextures. The textures are licensed under the cc0 license, which is great.
But if we don't sign up as a patron we only have access to 1k resolution textures. They have, in my opinion, nice quality assets. But the website could be better. The contrast ins't great and the text is fairly small making it slightly difficult to get a good overview at a glance. The search feature does not show any preview images in the results and many of the previews that are there are fairly low resolution and doesn't do the materials justice. Downloads are also server with Google Drive.
But if you become a patron it is well worth it and you get access to high quality materials that you can use in your Blender projects without much hassle. Website: Textures. Formely cgtextures. You can get a free account that gives you 15 credits per day but it only allows you to download a handful of low resolution textures. Some assets can cost several hundred credits making this site very expensive in comparison. But they have such a vast library that sometimes it is the only source you will be able to find certain assets.
I personally use this site less and less but on occasion I find myself browsing their library and downloading some assets. A couple of examples are their 3D scanned alpha masked atlas sheets and decals. Website: Source. It is pretty hard to put substance source by itself since it is part of the substance subscription.
Substance is an entire package including multiple applications such as Substance painter, Substance Designer and Alchemist to create textures for 3D procedurally. The library itself is large with a bit over assets. On top of that you have the substance suite to create your own assets for a very competitive price. Website: Textureninja. If you are on the hunt for plain old textures this is a great site to look at. It has a library with around image textures that you can use under the CC0 license.
Some images are also great for reference when modeling certain objects or details. Website: 3DAssets. Instead, it is a search engine that searches through these texture sites that are mentioned above among with some smaller contributors. Why is this so? Because we haven't assigned any UV coordinates to our Spheroid yet. Remember that although the Cube looks like a Spheroid now, this is only due to the effect of the assigned Subdivision Surface modifier.
The UV coordinates work at the lowest level of subdivision, which is still a six-faced Cube. Then go out of Edit Mode to update the Rendered preview. The Texture Coordinate node is not mandatory to map an image texture on an unwrapped object; in such a case, Cycles will automatically use the first available UV coordinates to map the image map anyway.
Often, the only Texture Coordinate node is not enough. What we need now is a way to offset, rotate, and scale this texture on the surface:. First delete the Bump node, then select the Texture Coordinate node, and drag it to the left of the window as far as suffices to make room for a new node.
In the Add menu, go to Vector and choose Mapping. Grab the Mapping node in the middle of the link that connects the Texture Coordinate node to the Checker Texture node. It will be automatically pasted between them, as shown in the following screenshot:. Now start playing with the values inside the Mapping node.
The Min and Max buttons on the bottom of the Mapping node are used to clip the extension of the texture mapping. Check both Min and Max to prevent the texture from being repeated n times on the surface, and it will be shown only once.
A minimum value of 0. You can tweak these values to limit or extend the clipping. This is useful to map decals, logos, or labels, for example, on an object and avoid repetition. In Cycles, it is possible to use normal maps by adding the Normal Map node by navigating to Add Vector Normal Map and connecting its output to the Normal input socket of the shader nodes.
Here is a link to the official documentation talking about the Normal Map node:. The main characteristic of the Cycles World is that it can emit light, so it practically behaves as a light source. Actually, its effect is the famous Global Illumination effect. As in Blender Internal, the World is considered as a virtual dome at a large distance from the camera, never touching the scene's objects.
Nothing in the 3D scene can affect the World. Actually, only the World can emit light on the scene and the objects. This is where we see the usual Use Nodes button under the Surface tab. Although no node system for the World window is set by default, the World window already has a dark, medium gray color slightly lighting the scene. Delete the default Lamp or put it in a different and disabled layer to see that the Spheroid in the scene is dark but still visible in the rendered 3D viewport.
It's already possible to change this gray color to some other color by clicking on the Color button right under Use Nodes the color at the horizon. This brings up the same color wheel that we saw for the shader colors. Set the color to R 0. Note that both the intensity and the general color graduation of the World are driven by this color. To have more light, just move the Value slider the vertical slider to a whiter hue. To give a general color mood to the scene, pick a color from inside the wheel.
This will affect all of the scene's illumination but will show the effect mainly in the shadows, as shown in the following screenshot:. To the right is the color wheel to set the World's color, inside the World window, under the main Properties panel. However, to get access to all the options for the World, we have to initialize it as a node system, which is shown in the following steps:. Look at the bottom header of the Node Editor window.
On the left-hand side of the material data block, there are two little icons: a little cube and a little world. The cube icon is used to create materials, while the world icon is for the World. At the moment, because we were working on the Spheroid material, the cube icon is the one selected. Click on the little world icon. The material's node disappears, and the Node Editor window is empty now because we entered the World mode.
Check the little Use Nodes box on the right of the data block to make a default world material appear. Alternatively, go to the World window under the Properties panel and click on the Use Nodes button under the Surface tab. Just like the materials, the default material for the World is simply made up of two nodes. A Background node is connected to a World Output node. In the Background node, there are two setting options: the Color box and the Strength slider. Both of them are quite self-explanatory.
Now, perform the following steps:. Go to the World window under the Properties panel, and click on the little square with a dot to the right side of the Color slot. From the resulting menu, select the Sky Texture node item. This replicates a physical sky model with two Sky types, an atmospheric Turbidity value slider, a Ground Albedo value slider, and a Strength slider, as shown in this screenshot:.
Note that you can also modify the incoming direction of the light, that is, the location of the sun, by rotating the sphere icon inside the node interface. This control isn't that much precise, by the way, and will hopefully improve in the future. The next steps are as follows:. Click on the Color button, which is now labeled Sky Texture , under the Surface tab in the Properties panel, and select the Environment Texture node to replace it, as shown in the following screenshot:.
The pink warning effect of a missing texture in the Environment Texture node of the World setting. Look in the Rendered view. You'll see that the general lighting has changed to a pink color. This is to show that the World material is now using an image texture to light the scene, but that there is no texture yet.
Click on the Open button in the World window, either under the Properties panel or in the recently added node inside the Node Editor window.
To appreciate the effect, click on the little eye icon on the side of the Lamp item in the Outliner to disable its lighting. Actually, you can see the image as a background in the Rendered preview. You can also rotate the viewport and watch the background texture, pinned to the World coordinates, rotate accordingly in real time. As for the object's materials, the mapping of any texture you are going to use for the World can be driven by the usual Mapping and Texture Coordinates nodes we have already seen.
Generally, for the World materials, only the Generated coordinates output should be used, and actually, the Generated coordinates output is used by default if no mapping method is specified.
Add the Mapping and Texture Coordinates nodes and connect them to the Vector input socket of the Environment Texture node, as shown in the following screenshot:. Now let's imagine a case in which we want to assign a texture to the World material and use it for the general lighting of the scene, but we don't want it to show in the background of the render.
In other words, we are using the HDR image to light the Spheroid and the Plane, but we want the two objects rendered on a uniform blue background; so how do we do it? This is how:. One way is to go to the Render window and check the Transparent option under the Film tab. This will show our Spheroid and Plane rendered in both the 3D viewport and the effective final rendered image on a transparent background, with a premultiplied alpha channel, as shown in the following screenshot:.
Now we can compose the rendered image with a blue background, both in external image editing software such as GIMP, to stay inside FOSS or directly in the Blender compositor. A different way to render the two objects on a uniform blue background is to use a Light Path node:. If this is the case, deselect the Transparent item checkbox in the Render window to restore the sky background in the preview and in the rendering.
Select the Background node in the Node Editor window. Connect its output to the second input socket of the Mix Shader node. Click on its Color box to change the color to R 0.
The objects in the scene are lit by the HDR image connected to the first Background node, but they appear in a sky that is colored as set in the Color box of the second Background node. The use of the Path Light node as a factor to have a different background than the HDR image still illuminating the scene.
To explain this trick better, let's say we just created two different world materials: the first material with the texture and the second material with a plain blue color this is not literally true; actually, the material is just one, containing the nodes of two ideally different worlds.
We mixed these two materials using the Mix Shader node. The upper green socket of the Mix Shader node is considered equal to a value of 0. As the name suggests, the Light Path node can set the path for the rays of light that are shot from the camera, if you remember. Is Camera Ray means that only the rays directly shot from the camera have a value of 1. Thus, because the textured world is connected to a socket equal to the value of 0. The World of the blue sky, which is connected to the input socket of value 1.
Just after the Surface subpanel, in the World window, there is the Ambient Occlusion subpanel. Ambient occlusion is a lighting method used to emphasize the shapes or the details of a surface, based on how much a point on that surface is occluded by the nearby surfaces. Ambient occlusion can replace the Global Illumination effect in some cases, though not the same. For example, to render interiors with fast and noise-free results, ambient occlusion is a cheap way to get an effect that looks a bit like indirect lighting.
There is a checkbox to enable Ambient Occlusion , along with the following sliders:. Factor : This is used for the strength of the ambient occlusion. Distance : This is the distance from a shading point to the trace rays.
A shorter distance emphasizes nearby features, while a longer distance takes into account objects that are further away. Instead, the transparency of a surface is taken into account. For example, a half-transparent surface will only half-occlude other surfaces. In this recipe, we will see how to create a mesh-light material to be assigned to any mesh object and used as a source to light the scene.
Until now, we have used the default Lamp a Point light already present in the scene to light the scene. By enabling the node system for the Lamp, we have seen that it uses a material created by connecting an Emission node to the Lamp Output node. The good news is that just because it's a material node, we can assign an Emission shader to a mesh, for example, to a Plane conveniently located, scaled, and rotated to point to the scene that is the center of interest. Such a light-emitting mesh is called a mesh-light.
Being a mesh, the Emission shader node output must be connected to the Surface or the Volume input socket of a Material Output node instead of the Lamp Output node. Light emission coming from a surface and not from a point is a lot more diffused and softer than the light from a Lamp. A mesh-light can be any mesh of any shape, so it can be used as an object taking part in the scene and be the real light source of the rendering at the same time, for example, a table lamp, or a neon sign, or a television screen.
As a pure light-emitting Plane, it's usually used as a sort of photographic diffuser. Two or three strategically placed mesh-lights can realistically simulate a photo studio situation. To replace the Lamp with a mesh-light, Plane perform the following steps:. Check the Copy Attributes Menu box to the right-hand side of the 3D View option, and click on the Save User Settings button in the bottom-left corner of the panel.
Then close the panel. Click on the Cursor to Selected item. Press Shift and select the Lamp. Now you have both the recently added Plane and the Lamp selected, and the latter is the active object. Right-click on the Lamp in the 3D view and press X to delete it. Put the mouse pointer on the 3D view and press 0 from the numeric keypad to go to Camera view. Now let's create the emission material and also take a look at the setup for the softness of the projected shadows:.
Select the Emitter plane and click on the little cube icon on the header of the Node Editor window. Click on the New button in the header and rename the material as Emitter. Leave the default color unchanged RGB 0. In the 3D view, scale the Emitter plane five times bigger press S , then enter 5 , and press Enter , and then set the Strength slider to 2.
Now look at the softer shadow, as shown in the following screenshot:. Now let's scale the Emitter plane a lot smaller press S , then type 0. Look at the crisper shadow in the Rendered preview, as shown in this screenshot:. From steps 5 to 7, we saw how a mesh-light can be scaled bigger or smaller to obtain a softer in the first case or a sharper in the second case shadow, respectively.
The Strength value must be adjusted for the light intensity to remain consistent, or the mesh-light must be moved closer or more distant from the scene. Scaling the mesh-light is basically the same as setting the size value for a Lamp. For Lamps, the softness of shadows can be set by the Size value to the left of the Cast Shadow option in the Lamp window, under the Properties panel by default, the Size value is set to 1.
At a value of 0. If the Size value is increased, the softness of the shadow increases too. Unlike the mesh-light, varying the Size value of a Lamp doesn't require us to adjust the Strength value to keep the same light intensity.
In several cases, you might not want the emitters to appear in your rendering. There are node arrangements to accomplish this such as using the Light Path node in a way quite similar to the Setting the World material recipe we have seen before , but the easiest way to do this is as follows:. Press the 3 key to navigate to the Side view. With the Emitter plane still selected, navigate to the Object window under the Properties panel. Look at the Ray Visibility tab usually at the bottom of the Properties panel , where there are five items: Camera , Diffuse , Glossy , Transmission and Shadows , with the corresponding checked boxes.
Uncheck the Camera item and watch the Emitter plane disappear in the rendered 3D window, but the scene still lit by it, as shown in the following screenshot:. Disabling the Camera item in the Ray Visibility subpanel to hide the mesh-light Plane from the rendering.
When you disable any one of the items, the corresponding property won't take part in the rendering. In our case, when the Camera box is unchecked, the mesh-light won't be rendered but it will still emit light.
Be careful that the Emitter plane is not renderable at this moment, but because all the other items in the tab are still checked, it can be reflected and could cast its own shadow on other objects. Now reselect the Spheroid remember that unless you have renamed it, its name in the Outliner remains as Cube.
Next, from the Ray Visibility tab in the Object window under the Properties panel, uncheck the Camera item. Now the Spheroid has disappeared, but it's still casting its shadow on the floor Plane, as shown in this screenshot:. Disabling the Camera item to hide the Spheroid object from the rendering but keeping the shadows on the floor. Now check the Camera item again and uncheck the Shadow box.
In this case, the Spheroid is visible again but doesn't cast a shadow, as shown in the following screenshot:. Disabling the Shadow item to have the Spheroid object rendered but without the shadows on the floor Plane. Check the Shadow box for the Spheroid again, and select the floor Plane.
Go to the Material window under the Properties panel, and click on the New button to assign a new material Material.
The floor Plane is now acting as a perfect mirror, reflecting the Spheroid and the HDR image we formerly set in the World material. Go back to the Object window and reselect the Spheroid. In the Ray Visibility tab, uncheck the Glossy item and watch the Spheroid, which is still rendered but not reflected by the mirror floor Plane, as shown in the following screenshot:.
Of course, the Ray Visibility trick we've just seen is not needed for Lamps because a Lamp cannot be rendered at all.
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