摄像机
全景相机
Cycles supports several types of panoramic cameras which are described in detail below. Note that these cannot be displayed in non-rendered modes in the viewport, i.e. Solid mode; they will only work for the final render.
等距圆柱(ERP)
从摄像机的位置来渲染场景的全景视图,并使用等矩形投影,始终在 X 轴上渲染整个 360°,在 Y 轴上渲染 180°。
此投影与用于世界着色器的环境纹理兼容,因此可用于渲染环境贴图。要匹配默认贴图,将摄像机对象旋转设置为 (90、 0、 -90) 或沿正 X 轴指向。这对应于使用默认环境纹理映射查看图像中心。
- 最小纬度,最大
垂直视场角的限制。
- 经度 最小值、最大值
水平视场的角度限制。
等角立方体贴图面
Improves on Equirectangular by providing a more uniform distribution of rendered pixel of the spherical environment. This results in an image that has little variation in visual resolution for the entire spherical projection. This is in contrast to Equirectangular which can lose detail in the poles of the image. This is also in contrast to cube map projections which lose detail near the edges of each face.
This panorama type is great for virtual reality use cases where providing as much visual detail for a limited resolution is important.
A limitation over Equirectangular is that this method does not have longitude or latitude limits.
鱼眼
鱼眼镜头通常是具有强失真的广角镜头,可用于创建全景图像,例如圆顶投影,或作为艺术效果。
鱼眼等距 镜头将最好地匹配真实相机。它提供镜头焦距和视场角度,并将传感器尺寸考虑在内。
鱼眼等距 镜头并不对应于任何真实的镜头模型;它会提供一个圆形鱼眼,不考虑任何传感器信息,而是使用整个传感器。这是全圆顶投影的好镜头。
- 镜头
镜头焦距以毫米为单位。
- 视野
视野角度,要360度以上才能捕捉到整个环境。
鱼眼透镜多项式
通过指定四阶多项式的坐标来匹配现实世界的相机。
The projection works as follows. Pixels in the image are mapped to positions \((x, y)\) on the camera sensor in mm. A position on the sensor is mapped to a direction with spherical coordinates \((1, \theta, \phi)\) in radians as follows:
来自这个方向的入射光线然后被投射到相应的像素上。
这可用于对鱼眼和透视相机进行建模。
镜像球
渲染,就像拍摄反光镜面球的照片一样。在极少数情况下,这可以与为捕获环境而拍摄的类似照片进行比较。