Introduction to changing resolution scale
Learn about the different dynamic resolution and upscaling techniques in the different render pipelines.
Read time 3 minutesLast updated 4 hours ago
Important
The Built-In Render Pipeline is deprecated and will be made obsolete in a future release.
It remains supported, including bug fixes and maintenance, through the full Unity 6.7 LTS lifecycle.
For more information on migration, refer to Migrating from the Built-In Render Pipeline to the Universal Render Pipeline and Render pipeline feature comparison.
To reduce the amount of work for the GPU and speed up rendering, you can change the resolution of the image Unity renders. For example, you can render at a lower resolution when the frame rate of the application decreases.
When you change the resolution scale, Unity does the following:
- Renders at a lower resolution.
- Uses one of several upscaling technique to increases the resolution of the rendered image, so it matches the final image.
If you use the Universal Render Pipeline (URP) or the Built-In Render Pipeline, you can only use dynamic resolution on some platforms.
For more information, refer to:
- Dynamic resolution if you use URP or the Built-In Render Pipeline.
- Dynamic resolution in the High Definition Render Pipeline (HDRP)
Upscaling techniques
The upscaling techniques depend on the render pipeline you choose and the platform you build for.
The Built-In Render Pipeline always uses a filtering technique the GPU provides.
Feature | What the feature uses to upscale the image | URP | HDRP |
|---|---|---|---|
| Bilinear | The bilinear or linear filtering the graphics API provides. | Yes. Refer to quality settings in the URP asset | No. |
| Nearest-neighbor | The nearest-neighbor or point sampling filtering the graphics API provides. | Yes. Refer to quality settings in the URP asset | No. |
| Catmull-Rom | Four bilinear samples. | No | Yes. Refer to Choose an upscale filter in HDRP. |
| AMD FidelityFX Contrast Adaptive Sharpen (CAS) | Contrast levels. | No | Yes. Refer to Choose an upscale filter in HDRP. |
| Temporal Anti-Aliasing Upscaling (TAAU) | Data from previous frames. | No | Yes. Refer to Choose an upscale filter in HDRP. |
| Spatial-Temporal Post-processing (STP) | Multiple input textures. STP configures itself automatically to provide the best balance of performance and quality based on the platform. | Yes, but you can't use STP together with dynamic resolution. Refer to Upscaling resolution in URP with STP. | Yes, but you can't use STP together with software dynamic resolution. Refer to STP in HDRP. |
| AMD FidelityFX Super Resolution (FSR) 1 | The frame buffer. | Yes. Refer to quality settings in the URP asset. | Yes. Refer to Choose an upscale filter in HDRP. |
| AMD FidelityFX Super Resolution (FSR) 2 | Multiple input textures. | No | Yes. Refer to Choose an upscale filter in HDRP. |
| AMD FidelityFX Super Resolution (FSR) 3 | Multiple input textures. | Yes, if you install the AMD built-in package and add FSR3 to the Upscaler Priority list. Refer to the Quality section of the URP Asset. | Yes, if you install the AMD built-in package and add FSR3 to the Advanced Upscalers By Priority list. |
| AMD FidelityFX Super Resolution (FSR) 4 | Multiple input textures. | Yes, if you install the AMD built-in package and add FSR4 to the Upscaler Priority list. Refer to the Quality section of the URP Asset. | Yes, if you install the AMD built-in package and add FSR4 to the Advanced Upscalers By Priority list. |
| NVIDIA Deep Learning Super Sampling (DLSS) 4 Super Resolution | Multiple input textures. | No | Yes. Refer to DLSS in HDRP. |
Alpha output with upscaling
Some upscaling techniques, including STP and FidelityFX Super Resolution, reconstruct only the color channels of the image and leave the alpha channel undefined. If you enable the Alpha Processing setting in the Post-processing section of the URP asset, for example to composite your rendered image with other content, Unity automatically rebuilds the alpha channel after upscaling. You don't need to enable any additional setting for the rebuild itself.
Unity rebuilds the alpha channel with the same temporal technique that Temporal Anti-aliasing (TAA) uses. It reprojects the alpha values from previous frames with motion vectors and blends them with the current frame. This gives better results than simple spatial upsampling, such as nearest-neighbor or bilinear filtering. However, after a camera cut or other sudden scene change, the alpha channel can take a few frames to settle.