Version: 2022.3
LanguageEnglish
  • C#

Graphics.DrawProceduralIndirectNow

Suggest a change

Success!

Thank you for helping us improve the quality of Unity Documentation. Although we cannot accept all submissions, we do read each suggested change from our users and will make updates where applicable.

Close

Submission failed

For some reason your suggested change could not be submitted. Please <a>try again</a> in a few minutes. And thank you for taking the time to help us improve the quality of Unity Documentation.

Close

Cancel

Declaration

public static void DrawProceduralIndirectNow(MeshTopology topology, ComputeBuffer bufferWithArgs, int argsOffset);

Declaration

public static void DrawProceduralIndirectNow(MeshTopology topology, GraphicsBuffer bufferWithArgs, int argsOffset);

Parameters

topology Topology of the procedural geometry.
bufferWithArgs Buffer with draw arguments.
argsOffset Byte offset where in the buffer the draw arguments are.

Description

Draws procedural geometry on the GPU.

DrawProceduralIndirectNow does a draw call on the GPU, without any vertex or index buffers. If the shader requires vertex buffers, one of the following occurs depending on platform: - If the vertex buffer is declared but the compiler can optimize it away, the normal DrawProcedural call occurs. - If the compiler is not able to optimize the vertex buffer declaration away, the draw call will be converted into a normal mesh drawing call with emulated vertex buffers injected. The latter option has performance overhead so it is recommended not to declare vertex inputs in shaders when using DrawProceduralIndirectNow.

This function only works on platforms that support compute shaders.

The amount of geometry to draw is read from a ComputeBuffer. Typical use case is generating an arbitrary amount of data from a ComputeShader and then rendering that, without requiring a readback to the CPU.

This is mainly useful on Shader Model 4.5 level hardware where shaders can read arbitrary data from ComputeBuffer buffers.

Buffer with arguments, bufferWithArgs, has to have four integer numbers at given argsOffset offset: vertex count per instance, instance count, start vertex location, and start instance location. This maps to Direct3D11 DrawInstancedIndirect and equivalent functions on other graphics APIs. On OpenGL versions before 4.2 and all OpenGL ES versions that support indirect draw, the last argument is reserved and therefore must be zero.

Note that this call executes immediately, similar to Graphics.DrawMeshNow. It uses the currently set render target, transformation matrices and shader pass.

There's also similar functionality in CommandBuffers, see CommandBuffer.DrawProceduralIndirect.

Additional resources: Graphics.DrawProceduralNow, ComputeBuffer.CopyCount, SystemInfo.supportsComputeShaders.


Declaration

public static void DrawProceduralIndirectNow(MeshTopology topology, GraphicsBuffer indexBuffer, ComputeBuffer bufferWithArgs, int argsOffset);

Declaration

public static void DrawProceduralIndirectNow(MeshTopology topology, GraphicsBuffer indexBuffer, GraphicsBuffer bufferWithArgs, int argsOffset);

Parameters

topology Topology of the procedural geometry.
indexBuffer Index buffer used to submit vertices to the GPU.
bufferWithArgs Buffer with draw arguments.
argsOffset Byte offset where in the buffer the draw arguments are.

Description

Draws procedural geometry on the GPU.

DrawProceduralIndirectNow does a draw call on the GPU, without a vertex buffer. If the shader requires vertex buffers, one of the following occurs depending on platform: - If the vertex buffer is declared but the compiler can optimize it away, the normal DrawProcedural call occurs. - If the compiler is not able to optimize the vertex buffer declaration away, the draw call will be converted into a normal mesh drawing call with emulated vertex buffers injected. The latter option has performance overhead so it is recommended not to declare vertex inputs in shaders when using DrawProceduralIndirectNow. The amount of geometry to draw is read from a ComputeBuffer. Typical use case is generating an arbitrary amount of data from a ComputeShader and then rendering that, without requiring a readback to the CPU.

This is mainly useful on Shader Model 4.5 level hardware where shaders can read arbitrary data from ComputeBuffer buffers.

Buffer with arguments, bufferWithArgs, has to have five integer numbers at given argsOffset offset: index count per instance, instance count, start index location, base vertex location, and start instance location. This maps to Direct3D11 DrawIndexedInstancedIndirect and equivalent functions on other graphics APIs. On OpenGL versions before 4.2 and all OpenGL ES versions that support indirect draw, the last argument is reserved and therefore must be zero.

Note that this call executes immediately, similar to Graphics.DrawMeshNow. It uses the currently set render target, transformation matrices and shader pass.

There's also similar functionality in CommandBuffers, see CommandBuffer.DrawProceduralIndirect.

Additional resources: Graphics.DrawProceduralNow, ComputeBuffer.CopyCount, SystemInfo.supportsComputeShaders.