How are vertex processors used in a GPU?
The commands, vertices, and state changes flow downstream, where they are used by subsequent pipeline stages. The vertex processors (sometimes called “vertex shaders”), shown in Figure 30-4, allow for a program to be applied to each vertex in the object, performing transformations, skinning, and any other per-vertex operation the user specifies.
How are vertex engines connected to fragment processors?
Because vertex processors can perform texture accesses, the vertex engines are connected to the texture cache, which is shared with the fragment processors. In addition, there is a vertex cache that stores vertex data both before and after the vertex processor, reducing fetch and computation requirements.
How are vertices fetched in a graphics pipeline?
Vertices and indices are fetched by the GPU as the first step in the GPU part of the pipeline. The performance of vertex and index fetching can vary depending on where the actual vertices and indices are placed.
Where does the command stream come from in a GPU?
First, commands, textures, and vertex data are received from the host CPU through shared buffers in system memory or local frame-buffer memory. A command stream is written by the CPU, which initializes and modifies state, sends rendering commands, and references the texture and vertex data.
How to pack vertex data in a shader?
To access each one in your shader, you would use the xy and zw swizzles. This allows you to pack your vertex data efficiently. Here is an example of an animated flip-book Shader. It uses the default inputs ( Position, Normal The direction perpendicular to the surface of a mesh, represented by a Vector.
How do you add a particle to a shader?
See in Glossary by attaching your own data to particles; for example, attaching a “health” value to each particle. To pass this data into a Shader by adding one of the two custom streams, in the same way you would send any other stream to your Shader (see ParticleSystemRenderer.EnableVertexStreams ).