MIA Material - Practical Examples
This page uses the following shorthand notation for the mouse buttons:
Step 1 In order to make asphalt, we first create a new mia_x material, rename it and remove the reflectivity.
Step 2 Asphalt is dark, so we lower the color slider in the diffuse options of the material. Applied to the floor of our scene, however, the asphalt still looks very light.
Step 3 In order to make our material behave more like asphalt, we lower the weight. This makes our material absorb more light, thus become darker. Furthermore, we increase the roughness a bit and our simple asphalt texture is finished. We can add more structure to it by using a procedural texture or bump
Using the reflectivity attributes, we will now make a cast floor. A cast floor is usually very glossy and has a smooth reflection.
Step 1 First, we create a new mia_x material, rename it and change its color to the grey we want.
Step 2 After setting the reflectivity to 1 because our floor is very smooth, we see that the material has a very clean reflection. We however want it to look more glossy. Thus, we lower the values for glossiness which "spreads out" the highlight on the material and our material resembles a cast floor.
It is possible to make the seams of the brick with bump.
Step 1 First, we will make a new material, call it brick for example, and remove the reflection.
Step 2 We will now add a procedural texture to the diffuse color by clicking on the checker box next to the color. RMB-click grid. Because this example will apply the material to a cube, choose As projection.
Because it is a cube, we want the projection type of projection1 to be triplanar. Choose this from the drop down menu.
Step 4 Now, we will go to 'grid1' to change the attributes of the grid: here we will change the line and filler color to make it more brick-like.
Step 5 In order to change the proportions of the grid, click on the 'outgoing' arrow next to the grid name in the tab grid1.
To make the structure of your material more comprehensible, you can also go to the hypershade, select your material and click on input and output. In the workspace, the in- and output nodes for the chosen material will become visible. Then click on the node called place2dTexture2 that is connected to grid1.
Now you will see the placement information for the grid.
Step 6 In the 2d Texture Placement Attributes that appear, you can change the Repeat UV values in order to change the proportions and size of the bricks. U and V refer to the axes of the coordinate system for the 2d texture (which is now the grid we added). Right now, the values are 4.000 and 4.000. You can see this relation in the image of your grid node: 4 times 4 “square bricks” are displayed. Changing these values will change the grid.
Step 7 The bricks are still placed above each other – the horizontal seams do not alternate. In order to achieve this place a check mark at the ‘’stagger’’ option.
We now made the grid have the right color, and changed the 2d placement so that the proportions and stagger were right.
Step 8 We now want to add a bump so that it seems as if the bricks protrude slightly – just like a real brick wall. In order to do that, in the attributes of our material, we go to ‘’bump’’ and also add a grid to the overall bump by clicking on the checkered box, choosing ‘’As projection’’ and the grid. In the projection attributes, we change projection type to triplanar just like before. Also, because we want the bricks to be “in front”, we change the grid filler to white and the lines to black. In the work area of the hypershade, we can see that more nodes have been added to our material, and that there is also a grid with a place2dtexture to the bump node. Because the grid is not the same as the one for the bricks, the bump seams do not overlap with the color seams yet.
Step 9 We want the 2d texture placement attributes of the grid for the bump to be the same as the ones that we changed for the diffuse color grid of the brick. We could copy the values, but if we changed one of them, we would have to change the other too. A way that prevents this is to connect the 2d placement for the color grid that we already changed to the grid of the bump. That way, one placement node is used for the two grids (color and bump). In order to do that we first delete the place2dtexture of the bump grid. Then MMB-drag the place2dtexture of the color grid onto the bump grid (Click on the place2dtexture texture using your Middle Mouse Button, hold it and drag it to the bump grid and then release the MMB). After releasing your mouse button, choose default from the menu. Both grids now have the same placement attributes. When rendering, the seams now appear to be indented. However, when zooming, the edge of the object is still smooth: the seams are only "visual", not a real displacement.
Cutting out a 2D person
The cutout opacity is very useful when one wants to add a person as a scale element.
Step 1 A plane is made to which a person is added as a texture. When making the plane, do not use interactive creation. This way, you can scale your plane so that its dimensions are proportional to that of your image. Next, make a new mia_x material, click on the checkered box next to its diffuse color and choose file, then your picture. The picture of the person you want to use should be in the sourceimages map of your project. To learn more about textures and their placement, take a look here. Press 6 in order to see textures.
The whole picture is now visible on the plane. However, you only want the person to be visible. For this, we have to connect a picture to the cutout opacity of your material that is black where the material should be invisible. Hence, you need a second picture where the person is white and their surroundings black. There is a screenshot of a practical layer structure in Photoshop to achieve this:
1: (make the background a layer with alt+double click on it) use a mask on the layer of the image to make the unwanted parts invisible
2: use the layer effect color overlay with white
3: put a new layer filled with black underneath. This way you can see white parts you missed very well and correct the silhouette of the person easily in the mask.
Step 3 Now, go to the Advanced options of the material for the plane, click on the checker box next to the slider and choose the black and white file of your person. Do not forget to turn on Alpha is Luminance in the Color Balance options of your file. Now the parts that are black in image coupled to cutout opacity have become invisible.
- Picture taken from http://farm4.static.flickr.com/3008/2641321627_8971b79b0e.jpg?v=0