The ability to (-rendering) (+render) realistic looking human skin is a must for any modern Video Game engine. To fulfill this need, Unreal Engine 4 (UE4) now offers a shading method specifically for skin or wax like surfaces called Subsurface Profile. While the Subsurface Profile shading model has similar properties to the Subsurface shading model, its key difference is in how it renders. SubsurfaceProfile uses a rendering approach that is based in Screen Space because this helps to better display the subtle subsurface effects seen in human skin where backscattering is a secondary effect only seen in few cases like ears for example. The following document will cover what a Subsurface Profile is and how you can use them in your work.
> What is a Subsurface Profile
The Subsurface scattering profile stores information about how the Subsurface scattering is supposed to be rendered. It can be created, shared, and saved in the Content Browser just like any other Actor. Subsurface scattering profiles work by storing artist driven data about the distance the light in the Subsurface should scatter, the color of the Subsurface, and the falloff color of the light once it has exited the object. This data can then be applied to a Subsurface Material to (-effect) (+affect) what the Subsurface looks like. Subsurface profile can also be tweaked interactively which means that you do not need to re-compile the material to see the results of edits.
> Enabling, Creating, and Using a Subsurface Profile
To use a Subsurface Profile in a Material, you must first enable the Material to use a Subsurface Profile by setting the Shading Model to Subsurface Profile in the Details panel of the Material. You can override the Subsurface Profile that is (-use) (+used) for this Material by inputting a different Subsurface Profile in the Subsurface Profile input.
Falloff Color: The Falloff Color defines the material scattering color once the light has entered the material. You should avoid using a vivid color if you want to get a more complex shading variation over (+the) area you see the scattering.
> Technical Details
The Subsurface scattering profile is based on work from (-the work from) Jimenez. Make sure to check out his webpage for many useful tips on how to make your 3D images look more realistic.
For this reason, unless you are certain that your change needs to propagate throughout all other instances of the function, it may be wise to make a copy of an existing function in the Content Browser (right-click and choose Make a Copy from the context menu) (+rather) than editing the original material function.
> > FunctionInput Nodes
As stated, (-MaterialInput) (+Material Input) nodes serve as the gateway through which data will enter a material function. A given function may have any number of these input nodes, each corresponding with an input pin that will appear on the function itself.
> Previewing
Function input nodes have some options for specifying preview values, since they do not know the actual values (-they) (+that) will be used with in a material. Each input has a built in PreviewValue (+that) can be used to show a constant for float input types. Function inputs also have a âPreviewâ connector which allows you to override that built in value with any value that matches the inputâs type. In this example, a texture sample has been used to provide the preview for a float 3 input.
> Input and Output
âMaterial Parameters, such as Scalar and Vector Parameters, cannot exist within Functions. This is to avoid any potential crosstalk that might occur when multiple instances of a Function are used in a single Material. To send data into a Function from a Parameter, you must use a FunctionInput node within the Function, and connect your Parameter in from outside, in the Material itself.â
> Parameters
âFunctions can now contain parameter node types. These parameters can be passed directly to any material for use.â
The information under the âParametersâ heading is in direct conflict with the information under the âInput and Outputâ heading.
The information under the âParametersâ heading appears to take presedence.
âEditing Material Functionsâ says âThis document assumes a working knowledge of the concept of material functions. For more information, see the Material Function Overview page.â
In the table of contents:
put âMaterial Functions Overviewâ
above âEditing Material Functionsâ
> Creating & Editing Material Parameter Collections
2. The Material Parameter Collection will be added and saved to the Content Browser just like any other (-Actor) (+Asset).
> Updating Material Parameters Collections Through Blueprints
"4. Once the Level Blueprint has been opened, it is now time to begin laying down some nodes. For this example we will be needing the following nodes and variables.
Float Variable Named: Des"
Okay. Something is missing . Does this document assume a familiarity with blueprints? I have done some playing with them so I know how to add getters and setters, and create variables, but others may not. The documentation should include instructions for these steps.
Perhaps take that bullet and turn it into step #5 and increment all the proceeding instructiosn accordingly.
The video below this paragraph needs to be updated for Unreal Editor 4.9. Also, the video does not demonstrate changing the name of the track.
> Overview
As a feature, Layered Materials exist as an extension Material (-Functions) (+Function). Functions, as you may recall, are self-contained node networks that perform a specific operation, such as a complex math equation. These functions can then be reused at will in any number of Materials. Because of the Make Material Attributes and Break Material Attributes nodes, functions can also be used to define a Material, entirely within a Function. Then, by bringing those functions into a final Material, you (+can) have (-then) a Layered Material.
It is important to realize that since Material Functions cannot be applied directly to a surface, you need (+to) bring your Material Layer functions into a new Material, which can then be applied to your objects. The great thing about this is that you can bring in as many Material Layers as you wish, blending them together however you see fit.
> Instancing Layered Materials
âBecause Layered Materials are essentially Material Functions, parameterizing them for instancing requires a little bit of extra forethought. Parameter expressions, such as Scalar and Vector Parameters, cannot exist within a function. To use them, you must create a Function Input expression as a part of the Material Layer. You can then connect a parameter into this input from the top-level Material. See the Material Functions overview for more information.â
This is no longer true, but it could be valuable to leave the rest of the information intact.
I would re-write that paragraph similar to:
âBecause Layered Materials are essentially Material Functions, parameterizing them for instancing requires a little bit of extra forethought. To make better use of Scalar and Vector Parameters, you can create a Function Input expression as a part of the Material Layer. You can then connect a parameter into this input from the top-level Material. See the Material Functions overview for more information.â
As a matter of consideration, I think I may have gotten a correction wrong. I made the correction within the context of the surrounding text instead of the whole paragraph.
âAs a feature, Layered Materials exist as an extension Material (-Functions) (+Function). Functions, as you may recall, are self-contained node networks that perform a specific operation, such as a complex math equation. These functions can then be reused at will in any number of Materials. Because of the Make Material Attributes and Break Material Attributes nodes, functions can also be used to define a Material, entirely within a Function. Then, by bringing those functions into a final Material, you (+can) have (-then) a Layered Material.â
In the above paragraph I corrected (Functions) to (Function) however, this may have been the wrong correction. Please review this content, as the more appropriate correction may have been to change (extension Material Functions) to (extension of Material Functions.) Since I didnât create the jargon it would be up to you to decide which is more appropriate. It seems to me upon review that my secondary edit appears to be more appropriate.
The post process settings are all of the properties of the various post process effects that can be controlled or overridden. These properties are declared in the UScene class. The PostProcessVolume contains (-a) (+an) FPostProcessSettings struct as its Settings property that contains all of these properties and allows them to be overridden by the volume.
Could you please improve the documentation on this topic ?
It clearly lack on information on the different function that you can override, what the purpose of them and how to setup them for the Game, Client, Server, Editor output.
For example: SetupBinaries,SetupGlobalEnvironment,ShouldCompileMonolithic,GUBP_GetPlatforms_MonolithicOnly,GUBP_GetConfigsForFormalBuilds_MonolithicOnly
The sample like ShooterGames do not configure it like it said in the sample on the documentation page.
Itâs very confusing and itâs hard to learn as nothing has been made in the same way.
Thanks for the update on this! I have gone onto this page an fixed up the wording on this paragraph to clear up any confusion. This will show live after the next publishing.
I have added âanâ and removed the âaâ from this paragraph.
Thank you for posting about this issue. It seems that mobile devices are repeating words in the URL. You can see this if you click on the link that you have provided as âEngineâ should only appear once and not twice.
I have entered UEDOC-2345 into out database so that we can resolve this issue.
âThe defaults of CircleDOF are intentionally weak to be more pleasant. To get the maximum effect you can tweak settings. Use a low Aperture for a large Bokeh, get close to an object and change the Field of View to be lower. Play with the focal distance toâ
I put that in quotes because thatâs all there is. It appears as though someone published this page in mid-editing. Possibly this was an accident? In any event, Fixing that paragraph could be a very welcome addition to the quality of the content for this heading.