## C Specification

To record a dispatch using non-zero base values for the components of WorkgroupId, call:

void vkCmdDispatchBase(
VkCommandBuffer                             commandBuffer,
uint32_t                                    baseGroupX,
uint32_t                                    baseGroupY,
uint32_t                                    baseGroupZ,
uint32_t                                    groupCountX,
uint32_t                                    groupCountY,
uint32_t                                    groupCountZ);

or the equivalent command

void vkCmdDispatchBaseKHR(
VkCommandBuffer                             commandBuffer,
uint32_t                                    baseGroupX,
uint32_t                                    baseGroupY,
uint32_t                                    baseGroupZ,
uint32_t                                    groupCountX,
uint32_t                                    groupCountY,
uint32_t                                    groupCountZ);

## Parameters

• commandBuffer is the command buffer into which the command will be recorded.

• baseGroupX is the start value for the X component of WorkgroupId.

• baseGroupY is the start value for the Y component of WorkgroupId.

• baseGroupZ is the start value for the Z component of WorkgroupId.

• groupCountX is the number of local workgroups to dispatch in the X dimension.

• groupCountY is the number of local workgroups to dispatch in the Y dimension.

• groupCountZ is the number of local workgroups to dispatch in the Z dimension.

## Description

When the command is executed, a global workgroup consisting of groupCountX × groupCountY × groupCountZ local workgroups is assembled, with WorkgroupId values ranging from [baseGroup*, baseGroup* + groupCount*) in each component. vkCmdDispatch is equivalent to vkCmdDispatchBase(0,0,0,groupCountX,groupCountY,groupCountZ).

Valid Usage
• If a VkImageView is sampled with VK_FILTER_LINEAR as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_LINEAR_BIT

• If a VkImageView is accessed using atomic operations as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_STORAGE_IMAGE_ATOMIC_BIT

• If a VkImageView is sampled with VK_FILTER_CUBIC_EXT as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_CUBIC_BIT_EXT

• Any VkImageView being sampled with VK_FILTER_CUBIC_EXT as a result of this command must have a VkImageViewType and format that supports cubic filtering, as specified by VkFilterCubicImageViewImageFormatPropertiesEXT::filterCubic returned by vkGetPhysicalDeviceImageFormatProperties2

• Any VkImageView being sampled with VK_FILTER_CUBIC_EXT with a reduction mode of either VK_SAMPLER_REDUCTION_MODE_MIN or VK_SAMPLER_REDUCTION_MODE_MAX as a result of this command must have a VkImageViewType and format that supports cubic filtering together with minmax filtering, as specified by VkFilterCubicImageViewImageFormatPropertiesEXT::filterCubicMinmax returned by vkGetPhysicalDeviceImageFormatProperties2

• Any VkImage created with a VkImageCreateInfo::flags containing VK_IMAGE_CREATE_CORNER_SAMPLED_BIT_NV sampled as a result of this command must only be sampled using a VkSamplerAddressMode of VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE.

• For each set n that is statically used by the VkPipeline bound to the pipeline bind point used by this command, a descriptor set must have been bound to n at the same pipeline bind point, with a VkPipelineLayout that is compatible for set n, with the VkPipelineLayout used to create the current VkPipeline, as described in [descriptorsets-compatibility]

• For each push constant that is statically used by the VkPipeline bound to the pipeline bind point used by this command, a push constant value must have been set for the same pipeline bind point, with a VkPipelineLayout that is compatible for push constants, with the VkPipelineLayout used to create the current VkPipeline, as described in [descriptorsets-compatibility]

• Descriptors in each bound descriptor set, specified via vkCmdBindDescriptorSets, must be valid if they are statically used by the VkPipeline bound to the pipeline bind point used by this command

• A valid pipeline must be bound to the pipeline bind point used by this command

• If the VkPipeline object bound to the pipeline bind point used by this command requires any dynamic state, that state must have been set for commandBuffer, and done so after any previously bound pipeline with the corresponding state not specified as dynamic

• There must not have been any calls to dynamic state setting commands for any state not specified as dynamic in the VkPipeline object bound to the pipeline bind point used by this command, since that pipeline was bound

• If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used to sample from any VkImage with a VkImageView of the type VK_IMAGE_VIEW_TYPE_3D, VK_IMAGE_VIEW_TYPE_CUBE, VK_IMAGE_VIEW_TYPE_1D_ARRAY, VK_IMAGE_VIEW_TYPE_2D_ARRAY or VK_IMAGE_VIEW_TYPE_CUBE_ARRAY, in any shader stage

• If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used with any of the SPIR-V OpImageSample* or OpImageSparseSample* instructions with ImplicitLod, Dref or Proj in their name, in any shader stage

• If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used with any of the SPIR-V OpImageSample* or OpImageSparseSample* instructions that includes a LOD bias or any offset values, in any shader stage

• If the robust buffer access feature is not enabled, and if the VkPipeline object bound to the pipeline bind point used by this command accesses a uniform buffer, it must not access values outside of the range of the buffer as specified in the descriptor set bound to the same pipeline bind point

• If the robust buffer access feature is not enabled, and if the VkPipeline object bound to the pipeline bind point used by this command accesses a storage buffer, it must not access values outside of the range of the buffer as specified in the descriptor set bound to the same pipeline bind point

• If commandBuffer is an unprotected command buffer, any resource accessed by the VkPipeline object bound to the pipeline bind point used by this command must not be a protected resource

• baseGroupX must be less than VkPhysicalDeviceLimits::maxComputeWorkGroupCount[0]

• baseGroupX must be less than VkPhysicalDeviceLimits::maxComputeWorkGroupCount[1]

• baseGroupZ must be less than VkPhysicalDeviceLimits::maxComputeWorkGroupCount[2]

• groupCountX must be less than or equal to VkPhysicalDeviceLimits::maxComputeWorkGroupCount[0] minus baseGroupX

• groupCountY must be less than or equal to VkPhysicalDeviceLimits::maxComputeWorkGroupCount[1] minus baseGroupY

• groupCountZ must be less than or equal to VkPhysicalDeviceLimits::maxComputeWorkGroupCount[2] minus baseGroupZ

• If any of baseGroupX, baseGroupY, or baseGroupZ are not zero, then the bound compute pipeline must have been created with the VK_PIPELINE_CREATE_DISPATCH_BASE flag.

Valid Usage (Implicit)
• commandBuffer must be a valid VkCommandBuffer handle

• commandBuffer must be in the recording state

• The VkCommandPool that commandBuffer was allocated from must support compute operations

• This command must only be called outside of a render pass instance

Host Synchronization
• Host access to commandBuffer must be externally synchronized

• Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

Command Properties
Command Buffer Levels Render Pass Scope Supported Queue Types Pipeline Type

Primary
Secondary

Outside

Compute