Hi everyone,
I’m running into a reflection issue. I am an experienced programmer but relatively new to rendering, so I’d like to know if this is expected behavior or if my setup is wrong.
I have a very large flat water plane (just a simple static mesh plane with a water material), and in the middle of it I placed two cubes. To get reflections I added a Box Reflection Capture that wraps the cubes.
As you can see in the screenshot, the reflections are pushed all the way to the edges of the water plane instead of appearing near the cubes.
Here is information about my setup.
Global config:
Forward Shading: Enabled
Lumen: Disabled
Global Illumination Method: None
Reflection Method: None
Support global clip plane for Planar Reflections: Disabled
Ray Tracing: Disabled
Material:
Base node: Color black and roughness 0
Blend Mode: Translucent
Shading Model: Default Lit
Lighting Mode: Surface Translucency Volume
Screen Space Reflections: Disabled
Planar Reflections: Disabled
High Quality Reflections: Disabled
In the scene:
Box Reflection Capture with all settings by default.
When you’re in forward shading and you are not using HQ reflections, the closest cubemap will be selected and it will be projected as if it is an infinite distance from the camera.
I tried enabling High Quality Reflections in the material and rebuilt the reflection captures. Now the reflection is being pushed to the edges of the reflection area, but it’s still incorrect, as shown in the screenshot.
I also tried removing the reflection box, making my material opaque, and enabling planar reflections in both the project settings and the material, but that doesn’t seem to work either. There is no reflection at all.
Reflection captures just take a panoramic screenshot of the scene and project it into an arbitrary shape, since you’re using a box reflection capture, it will be projected into the shape of a box. They’ll never look correct except from the point they were captured at, and even then they’ll have distortion from the projection.
Generally speaking, reflection captures are only good for rough surfaces where the mismatch won’t be noticeable. For mirror quality, you’ll need to use planar reflections.
For planar reflections to work, you need to add a planar reflection actor to the scene and orient it where you need the reflection.
Keep in mind, planar reflections are expensive. You can use them (Epic has used them for VR projects that needed to run at very high framerates) just be aware you need to budget for it.
