Table of content :
- How to install the post-process pack ?
- How to add a post-process effect in my level ?
- Why one of the post-process material is not producing any results on screen ?
- How to update a post-process material at runtime ?
- How to control manually the speed of the “Pulse” post-process ?
- How to change the source location of the “Pulse” post-process ?
- Why some post-processes don’t appear properly in the editor ?
- Why some post-processes don’t work properly with Screen Percentage ?
How to install the post-process pack ?
You are now ready to use the package as you want. Take a look at the demo level located in the “Maps” folder to get an overview of all the effects.
How to add a post-process effect in my level ?
To add a post-process effect, a post-process volume is required. See the official documentation.
To add one of the post-process effects :
- Select a post-process instanced material from the “Instance” folder
- Select the post-process volume in your level
- Go the properties of the volume (via the “details” panel)
- Find the “blendable” section
- Add a new slot
- Use the arrow to load the material
The order of the materials in the blendable list doesn’t matter, as each material has its own priority value. For more information, see the documentation.
Why one of the post-process material is not producing any results on screen ?
Some of the post-process materials require additional engine features, which can be enable in the project settings. Make sure the “Custom Stencil” is enabled for example.
How to update a post-process material at runtime ?
There are two ways to control by blueprint/c++ a material during gameplay :
The first solution is the easiest to implement. Just replace the main blending parameter of the material by one from a parameter collection that you created.
How to control manually the speed of the “Pulse” post-process ?
The pulse post-process rely on a time variable by default. Open the “mat_pulse_force” material and simply replace the section before the “frac” node by a custom constant value. This value can be exposed as a parameter to be driven by gameplay code later. The range expected for the value must be between 0 to 1.
How to change the source location of the “Pulse” post-process ?
This change can be a bit tricky if you are not familiar with material editing. Open the “mat_pulse_force” material and replace the “camera relative world position” node by new nodes, as showed by the images below.
You can see the “constant 3” node, this the new source of the pulse effect in world space. You can convert this node as a parameter to control it during gameplay.
Why some post-processes don’t appear properly in the editor ?
This is because of a technical limitation of the unreal engine editor. Screen space UV coordinates are not updated properly for the viewport which can lead to “broken” effects like in the example below. The only way to visualize properly an effect is to use the “fullscreen” mode (by pressing F11) or by running your project as a standalone game.
Why some post-processes don’t work properly with Screen Percentage ?
Since the version 4.19.0 of the Unreal Engine the Screen Percentage feature has changed and some post-processes don’t work properly anymore. After some investigation on my side, the following post-process are not working properly if Screen Percentage is different from 100% :
- Pulse Wallhack
Unfortunately, those effects are broken because of engine bugs at the moment.
I have contacted Epic Games to submit them a bug report.