Introduction
There are 3 types of reflections in Unreal Editor for Aximmetry. This document will describe these 3 reflections.
All of the settings below are made in Unreal Editor for Aximmetry.
Screen Space Reflections
By default, the project uses screen space reflections if ray tracing, in general, is not enabled.
This is a very cheap effect in terms of performance however it produces very low-quality results with severe rendering artifacts. We recommend using planar or ray-tracing reflections instead.
There are some limitations when using screen-space reflections:
- Reflection textures provided by Aximmetry are ignored (The Mirror Offset, Mirror Feet Blur, and Feet Blur Offset settings have no effect.)
- If ray tracing is enabled: ray tracing ambient occlusion might cause a rendering error in the reflection if ray tracing shadows are enabled (the camera is in Ray Traced Shadows And Rasterized Reflections rendering mode). In this case, ray tracing ambient occlusion should be disabled:
- Add a Post Process Volume to your scene. To do this set the following settings in the Details panel:
- Check Post Process Volume Settings / Infinite Extent (Unbound)
- Uncheck Post Process Volume Settings / Rendering Features / Ray Tracing Ambient Occlusion / Enabled
Planar Reflections
Planar reflections provide high-quality results with a moderate performance impact. In general, we recommend using this type of reflection.
How to set up planar reflections is described in the Unreal Engine documentation.
Enable clip planes
- Go to Edit / Engine / Rendering / Lighting
- Enable Support global clip plane for Planar Reflections
Ray-traced Reflections
By default, the project uses ray-traced reflections if ray tracing, in general, is enabled. See more information.
The Unreal Engine ray tracing consists of multiple features that can be turned on or off individually.
Most of these features can be used with Aximmetry DE but there are some limitations due to the experimental nature of ray tracing in Unreal Engine.
Please be aware that all ray tracing features have a high-performance cost, even on modern hardware. We suggest that you disable all ray-tracing features and then enable the ones that benefit your scene the most. How to configure these settings is described here.
The camera supports most ray tracing features but there are some caveats due to limitations in the Unreal Engine:
- Ray-Traced Global Illumination is fully supported.
- Ray-Traced Reflections and Ray-Traced Shadows are supported, but only one of them can be enabled at a time.
- Ray-Traced Ambient Occlusion and Ray-Traced Translucency are not supported.
Currently, the camera can operate in 3 rendering modes:
- Rasterized Shadows And Rasterized Reflections
- Ray-Traced Shadows And Rasterized Reflections
- Rasterized Shadows And Ray-Traced Reflections
The mode can be selected in the Details panel of the camera, using the Aximmetry / Render Mode drop-down menu. The scene must be set up according to the selected mode to avoid rendering errors.
Rasterized Shadows And Rasterized Reflections
This is the default mode. The camera works the same way as before the introduction of ray tracing features. If you are using Ray Tracing, we recommend using this mode because it can produce high-quality results with good performance.
Setup (only required if Ray Tracing is enabled in the project):
- Disable ray-traced shadows for all the lights in the scene by unchecking Details / Light / Cast Ray Tracing Shadows
- Add a Post Process Volume. To do this set the following settings in the Details panel:
- Check Post Process Volume Settings / Infinite Extent (Unbound)
- Check Rendering Features / Reflections / Type and set it to Screen Space (Note: Despite the name, Planar Reflections still work and should be used instead of Screen Space Reflections)
- Select Rasterized Shadows And Rasterized Reflections in the Details panel of the camera using the Aximmetry / Render Mode drop-down menu.
Ray Traced Shadows And Rasterized Reflections
Setup:
- Enable Ray Tracing in the project as described here
- Enable ray-traced shadows for all the lights in the scene by checking Details / Light / Cast Ray Tracing Shadows. (This should be enabled by default.)
- Add a Post Process Volume. To do this set the following settings in the Details panel:
- Check Post Process Volume Settings / Infinite Extent (Unbound)
- Check Rendering Features / Reflections / Type and set it to Screen Space (Note: Despite the name, Planar Reflections still work and should be used instead of Screen Space Reflections)
- Select Ray Traced Shadows And Rasterized Reflections in the Details panel of the camera using the Aximmetry / Render Mode drop-down menu.
Rasterized Shadows And Ray Traced Reflections
Setup:
- Enable Ray Tracing in the project as described here
- Disable ray-traced shadows for all the lights in the scene by unchecking Details / Light / Cast Ray Tracing Shadows
- Add a Post Process Volume. To do this set the following settings in the Details panel:
- Check Post Process Volume Settings / Infinite Extent (Unbound)
- Check Rendering Features / Ray Tracing Reflections / Include Translucent Objects and check the box next to it
- Optional: Outdoor scenes where the talent's reflection can be seen in front of the sky require some additional setup:
- Select the Sky Sphere
- Select the SkySphereMesh component in the Details panel
- Check Rendering / Ray Tracing / Visible in Ray Tracing
- Select Rasterized Shadows And Ray Traced Reflections in the Details panel of the camera using the Aximmetry / Render Mode drop-down menu.
Limitations
Currently, some features cannot be fully supported due to limitations in the Unreal Engine:
- Ray-traced reflections and ray-traced shadows cannot be used at the same time.
- Setting the Mirror Offset of the billboard in Aximmetry to non-zero values produces rendering errors around the talent in certain cases when using ray-traced reflections.
- Brightness of the reflection of unlit billboards can be different from the actual billboard when using ray-traced reflections (depending on the scene exposure).
- Lighting does not affect the reflection of lit billboards when using ray-traced reflections.
- Rasterized shadows are not visible in ray-traced reflections.
- Ray-traced shadows are not visible in rasterized reflections.
- Ray-traced translucency is not supported. (Do not set Details / Rendering Features / Translucency / Type to Ray Tracing on the Post Process Volume.)
