Abstract: In a graphics processing system, a bounding volume 20 representing the volume of a scene to be rendered and a cube texture 30 representing the transparency of the surface of the bounding volume are defined. Then, when the scene is to be rendered for output, a color to be used to represent a first sampling point 25 as seen from a viewpoint position 24 for the scene is determined by determining, for each of plural second sampling points 27 along a vector 26 from the first sampling point 25 to the viewpoint position 24, a transparency parameter indicative of the amount of light that falls on the second sampling point 27, and then using the determined transparency parameter values for each of the plural second sampling points 27 to determine the color.

Abstract: In a graphics processing system, a bounding volume (20) representative of the volume of all or part of a scene to be rendered is defined. Then, when rendering an at least partially transparent object (21) that is within the bounding volume (20) in the scene, a rendering pass for part or all of the object (21) is performed in which the object (21) is rendered as if it were an opaque object.

Abstract: In a graphics processing system, a bounding volume (20) representing the volume of a scene to be rendered and a cube texture (30) representing the transparency of the surface of the bounding volume are defined. Then, when the scene is to be rendered for output, a vector (28) from a sampling point (25) being considered to a light source (22) external of the bounding volume is determined and then used to determine how to sample the texture that represents the transparency of the surface of the bounding volume to determine the transparency of the surface of the bounding volume between the sampling point and the light source. The so-determined transparency is then used to simulate the effect of shadows cast by the external light source (22) at the sampling point (25).

Abstract: In a graphics processing system, a bounding volume 20 representing the volume of a scene to be rendered and a cube texture 30 representing the transparency of the surface of the bounding volume are defined. Then, when the scene is to be rendered for output, a colour to be used to represent a first sampling point 25 as seen from a viewpoint position 24 for the scene is determined by determining, for each of plural second sampling points 27 along a vector 26 from the first sampling point 25 to the viewpoint position 24, a transparency parameter indicative of the amount of light that falls on the second sampling point 27, and then using the determined transparency parameter values for each of the plural second sampling points 27 to determine the colour.

Abstract: A graphics processing system for generating a render output using an input curve defined in a world space includes processing circuitry configured to determine a portion of a canonical curve defined in canonical space that corresponds to the input curve and the transformation needed to map the input curve to the portion of the canonical curve. For sampling points in the world space surrounding the input curve, the processing circuitry is configured to transform the sampling points from the world space to the canonical space using the determined transformation between the world space and the canonical space; and determine, in the canonical space, the closest point on the determined portion of the canonical curve to the transformed sampling point. The system also includes processing circuitry capable of using the determined closest points on the canonical curve for the transformed sampling points in the canonical space when generating a render output.