[[drawing-mesh-shading]] == Programmable Mesh Shading In this drawing approach, primitives are assembled by the mesh shader stage. <> operates similarly to <> as the shaders make use of workgroups. [open,refpage='vkCmdDrawMeshTasksNV',desc='Draw mesh task work items',type='protos'] -- :refpage: vkCmdDrawMeshTasksNV To record a draw that uses the mesh pipeline, call: include::{generated}/api/protos/vkCmdDrawMeshTasksNV.txt[] * pname:commandBuffer is the command buffer into which the command will be recorded. * pname:taskCount is the number of local workgroups to dispatch in the X dimension. Y and Z dimension are implicitly set to one. * pname:firstTask is the X component of the first workgroup ID. When the command is executed, a global workgroup consisting of pname:taskCount local workgroups is assembled. .Valid Usage **** include::{chapters}/commonvalidity/draw_common.txt[] * [[VUID-vkCmdDrawMeshTasksNV-taskCount-02119]] pname:taskCount must: be less than or equal to sname:VkPhysicalDeviceMeshShaderPropertiesNV::pname:maxDrawMeshTasksCount **** include::{generated}/validity/protos/vkCmdDrawMeshTasksNV.txt[] -- [open,refpage='vkCmdDrawMeshTasksIndirectNV',desc='Issue an indirect mesh tasks draw into a command buffer',type='protos'] -- :refpage: vkCmdDrawMeshTasksIndirectNV To record an indirect mesh tasks draw, call: include::{generated}/api/protos/vkCmdDrawMeshTasksIndirectNV.txt[] * pname:commandBuffer is the command buffer into which the command is recorded. * pname:buffer is the buffer containing draw parameters. * pname:offset is the byte offset into pname:buffer where parameters begin. * pname:drawCount is the number of draws to execute, and can: be zero. * pname:stride is the byte stride between successive sets of draw parameters. fname:vkCmdDrawMeshTasksIndirectNV behaves similarly to flink:vkCmdDrawMeshTasksNV except that the parameters are read by the device from a buffer during execution. pname:drawCount draws are executed by the command, with parameters taken from pname:buffer starting at pname:offset and increasing by pname:stride bytes for each successive draw. The parameters of each draw are encoded in an array of slink:VkDrawMeshTasksIndirectCommandNV structures. If pname:drawCount is less than or equal to one, pname:stride is ignored. .Valid Usage **** include::{chapters}/commonvalidity/draw_common.txt[] include::{chapters}/commonvalidity/draw_dispatch_indirect_common.txt[] include::{chapters}/commonvalidity/draw_indirect_drawcount.txt[] * [[VUID-vkCmdDrawMeshTasksIndirectNV-drawCount-02146]] If pname:drawCount is greater than `1`, pname:stride must: be a multiple of `4` and must: be greater than or equal to code:sizeof(sname:VkDrawMeshTasksIndirectCommandNV) * [[VUID-vkCmdDrawMeshTasksIndirectNV-drawCount-02156]] If pname:drawCount is equal to `1`, [eq]#(pname:offset {plus} code:sizeof(slink:VkDrawMeshTasksIndirectCommandNV))# must: be less than or equal to the size of pname:buffer * [[VUID-vkCmdDrawMeshTasksIndirectNV-drawCount-02157]] If pname:drawCount is greater than `1`, [eq]#(pname:stride {times} (pname:drawCount - 1) {plus} pname:offset {plus} code:sizeof(slink:VkDrawMeshTasksIndirectCommandNV))# must: be less than or equal to the size of pname:buffer **** include::{generated}/validity/protos/vkCmdDrawMeshTasksIndirectNV.txt[] -- [open,refpage='VkDrawMeshTasksIndirectCommandNV',desc='Structure specifying a mesh tasks draw indirect command',type='structs',xrefs='vkCmdDrawMeshTasksIndirectNV'] -- The sname:VkDrawMeshTasksIndirectCommandNV structure is defined as: include::{generated}/api/structs/VkDrawMeshTasksIndirectCommandNV.txt[] * pname:taskCount is the number of local workgroups to dispatch in the X dimension. Y and Z dimension are implicitly set to one. * pname:firstTask is the X component of the first workgroup ID. The members of sname:VkDrawMeshTasksIndirectCommandNV have the same meaning as the similarly named parameters of flink:vkCmdDrawMeshTasksNV. .Valid Usage **** * [[VUID-VkDrawMeshTasksIndirectCommandNV-taskCount-02175]] pname:taskCount must: be less than or equal to sname:VkPhysicalDeviceMeshShaderPropertiesNV::pname:maxDrawMeshTasksCount **** include::{generated}/validity/structs/VkDrawMeshTasksIndirectCommandNV.txt[] -- [open,refpage='vkCmdDrawMeshTasksIndirectCountNV',desc='Perform an indirect mesh tasks draw with the draw count sourced from a buffer',type='protos'] -- :refpage: vkCmdDrawMeshTasksIndirectCountNV To record an indirect mesh tasks draw with the draw count sourced from a buffer, call: include::{generated}/api/protos/vkCmdDrawMeshTasksIndirectCountNV.txt[] * pname:commandBuffer is the command buffer into which the command is recorded. * pname:buffer is the buffer containing draw parameters. * pname:offset is the byte offset into pname:buffer where parameters begin. * pname:countBuffer is the buffer containing the draw count. * pname:countBufferOffset is the byte offset into pname:countBuffer where the draw count begins. * pname:maxDrawCount specifies the maximum number of draws that will be executed. The actual number of executed draw calls is the minimum of the count specified in pname:countBuffer and pname:maxDrawCount. * pname:stride is the byte stride between successive sets of draw parameters. fname:vkCmdDrawMeshTasksIndirectCountNV behaves similarly to flink:vkCmdDrawMeshTasksIndirectNV except that the draw count is read by the device from a buffer during execution. The command will read an unsigned 32-bit integer from pname:countBuffer located at pname:countBufferOffset and use this as the draw count. .Valid Usage **** include::{chapters}/commonvalidity/draw_common.txt[] include::{chapters}/commonvalidity/draw_dispatch_indirect_common.txt[] include::{chapters}/commonvalidity/draw_indirect_count_common.txt[] * [[VUID-vkCmdDrawMeshTasksIndirectCountNV-stride-02182]] pname:stride must: be a multiple of `4` and must: be greater than or equal to code:sizeof(sname:VkDrawMeshTasksIndirectCommandNV) * [[VUID-vkCmdDrawMeshTasksIndirectCountNV-maxDrawCount-02183]] If pname:maxDrawCount is greater than or equal to `1`, [eq]#(pname:stride {times} (pname:maxDrawCount - 1) {plus} pname:offset {plus} code:sizeof(sname:VkDrawMeshTasksIndirectCommandNV))# must: be less than or equal to the size of pname:buffer * [[VUID-vkCmdDrawMeshTasksIndirectCountNV-countBuffer-02191]] If the count stored in pname:countBuffer is equal to `1`, [eq]#(pname:offset {plus} code:sizeof(sname:VkDrawMeshTasksIndirectCommandNV))# must: be less than or equal to the size of pname:buffer * [[VUID-vkCmdDrawMeshTasksIndirectCountNV-countBuffer-02192]] If the count stored in pname:countBuffer is greater than `1`, [eq]#(pname:stride {times} (pname:drawCount - 1) {plus} pname:offset {plus} code:sizeof(sname:VkDrawMeshTasksIndirectCommandNV))# must: be less than or equal to the size of pname:buffer **** include::{generated}/validity/protos/vkCmdDrawMeshTasksIndirectCountNV.txt[] --