Basic Level Part 2
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Basic Level Editing Part 2
Load up your file from Editing Basic Level Part 1 which should be named "RBArenaBasicLevel_02.rbd" from the File->Open Menu. Ok good now we are going to lay down materials and textures on the floors, walls, and ceilings. The textures are already connected in the material editor so we do not have to hook them up in the materials editor. For more complete coverage of how to hook up textures to materials please go to:
Ok you are now going to click on the Browser Window.
When the new window pops up select file open and select all of the .upk files. Now you have a bunch of Materials and Textures. The textures are already applied to the materials for the game.
Ensure that there is a check next to 'Material is set' on the left side resource panel. If not, you will not see the maps you have imported. You should now have some materials and textures imported:
Applying Materials To The Floor
Select the PROP_Security circled in red and the select Ground_3 material circled in red on the right. Now select the floor and right click and select from the menu Apply Material: Ground_3. Now you have applied your first material. Move on to the area in front of you and select the ground in the hallway and the big room. Don't forget to hold down Ctrl key while you are selecting the surfaces to select more than one surface at once. Now right click and apply the Ground 3 Material in the same way.
Applying Materials To The Walls
Now go back to the starting room and the hallway and select all of the walls. Now select the wall_01 material. Right click on one of the selected walls and select the Apply Material: wall_01 from the menu.
Understanding How Materials Work
Now that you have the hang of it choose cool and interesting materials that go together. You may have noticed that I said materials and not texture like what was used in Unreal Engine 2. Unreal Engine 3 now makes use of shaders much more in the way film makes use of shaders which allows for interesting and realistic surfaces. Several textures can go together in a single material defining different aspects of the way the surface looks. Diffuse is your color channel where you would connect the color of the surface into this input. For instance, a color texture would be connected into this channel. Emissive channel is the channel that makes the surface glow. Specular is the shine spot on a surface and how it looks. The power of the specular refers to how bright the specular can be. It is possible to have values higher than 1.0 in which normal when you are dealing HDR images for image based lighting. Opacity determines if the surface is see through or not and by how much. The normal channel is for normal maps to give the surface lots of detail when the light hits the surface. Normal maps have replaced bump maps in the game industry because they do a much better job of giving the impression of detail being on a surface that is not there. The UVs on a surface define how the image will be wrapped around a 3D model since an image is flat and a model is not flat.
In this particular shader you may have noticed the multiply nodes along with the image maps aka textures. The multiply works just like in 3rd grade. Generally you are looking at numbers between 0.0 and 1.0 for color. There are 3 color channels which is the reason why a vector is used which is a variable that has 3 values. The 3 color channels are RGB, Red, Green, Blue, each value in the vector is a float which means a number that can have a decimal in it. The number color 1,1,1 is pure white where as 0,0,0 is pure black. Any number times itself is 0 and any number times 1 is itself. For this reason grey scaled images are preferred for multiplication. Here only 1 texture is used and yet because of smart use of shading knowledge on behalf of Naked Sky they were able to make the entire shader with just that 1 texture. Because white is 1 when they multiplied the blue color times that black and white image they got a blue and black image afterwards. A parameter is a definable value that can be changed on the fly where as a constant can not be changed. Which means the color of the lights on this material can be changed at any point and time. They then multiplied the white color constant times the blue and black image. Remember anything times 0 is 0 meaning anything times black is black so the only part that actually gets multiplied in this image is the blue times a very high value of white which in this case is 15.0. The result is a blown out white in the emissive channel which makes the material glow white. In the diffuse channel the blue and black node is plugged into the diffuse channel making the color of the material surface blue and black. We see this result to the left where the shader ball is black with blue edges before its blown out with a bright white glow. There are many other mathematical operations and features that can be done in the Unreal 3 Editor for shading and to discuss them at length would span many books.
By Nate Nesler