Размытие изображения камеры (Camera Motion Blur)
Motion Blur is a common postprocessing effect simulating the fact that for most camera systems ‘light’ gets accumulated over time (instead of just taking discrete snapshots). Fast camera or object motion will hence produce blurred images.
The current Motion Blur implementation only supports blur due to camera motion with the option to exclude certain layers (useful for excluding characters and/or dynamic objects, especially when those are following the camera movement). It can however be extended to support dynamic objects if an additional script keeps track of each objects model matrix and updates the already generated velocity buffer.
As with the other image effects, you must have the Standard Assets Effects package installed before it becomes available.
Свойства
| Свойство: | Функция: |
|---|---|
| Technique | Motion Blur algorithm. Reconstruction filters will generally give best results at the expense of performance and a limited blur radius of 10 pixels unless a DX11/GL3 enabled graphics device is used. |
| Velocity Scale | Более высокие значения делают изображение более замытым. |
| Velocity Max | Maximum pixel distance blur will be clamped to and tile size for reconstruction filters (see below). |
| Velocity Min | Минимальное расстояние в пикселях, при котором размытие полностью удаляется. |
Camera Motion specific:
| Свойство: | Функция: |
|---|---|
| Camera Rotation | Увеличивает силу размытия, основываясь на вращении камеры. |
| Camera Movement | Увеличивает силу размытия, основываясь на перемещении камеры. |
Local Blur, Reconstruction, ReconstructionDX11 and ReconstructionDisc specific:
| Свойство: | Функция: |
|---|---|
| Exclude layers | Объект на этом слое останется нетронутым. |
| Velocity downsample | Lower resolution velocity buffers might help performance but will heavily degrade blur quality. Might still be a valid option for simple scenes. |
| Sampler Jitter | Adding noise helps prevent ghosting for the Reconstruction filter. |
| Max Sample Count | Количество сэмплов определяющих силу размытия. Очень сильно влияет на производительность. |
| Preview (Scale) | Preview how blur might look like given artificial camera motion values. |
Фильтры размытия изображения (техника)
Local Blur simply performs a directional blur along the current’s pixel velocity. Being essentially a gather operation, it is suited for scenes with a low geometric complexity (e.g. vast terrains), large blur radii or when ‘realism’ is not the governing factor. One shortcoming is that it can’t produce proper ‘overlaps’ of blurred objects onto focused background areas. Another one that excluded objects ‘smear’ onto blurred areas.
Reconstruction filters can produce more realistic blur results. The name Reconstruction is derived from the fact that the filter tries to estimate backgrounds, even if there is no information available in the given color and depth buffers. The results can be of higher quality and shortcomings of the Local Blur’s gather filter can be avoided (it can e.g. produce proper overlaps).
It is based on the paper A Reconstruction Filter for Plausible Motion Blur (http://graphics.cs.williams.edu/papers/MotionBlurI3D12/). The algorithm chops the image into tiles of the size Velocity Max and uses the maximum velocity in the area to simulate a blurry pixel scattering onto neighbouring areas. Artifacts can arise if the velocity is highly varying while the mentioned tile size is large.
The DirectX11 / OpenGL3 exclusive filter ReconstructionDX11 allows arbitrary blur distances (aka tile size or Velocity Max) and creates nicer blurs by using more samples.
The ReconstructionDisc variation uses a different sampling pattern to generate a softer look compared to the standard Reconstruction filters. However, as more samples are taken (it scales automatically to DirectX11), the resulting cost can be higher.
While all of the above filters need a prepass to generate a velocity buffer, the Camera Motion filter solely works on the camera motion. It generates a global filter direction based on camera change and blurs the screen along that direction (see Post-Processing in Orange Box for more details). Данный эффект специально заточен под сглаживание изображения при быстром перемещении камеры, в качестве примера - в шутерах от первого лица.
Аппаратная поддержка
This effect requires a graphics card that supports Shader Model 3 and depth textures. Для более подробного ознакомления с темой и списком совместимых аппаратных средств, посетите страницу документации графические возможности аппаратных средств и их эмуляция.