I have a fbo generated by last frame, which contain a color texture and a depth texture. Then i want blit that fbo to current MTKView, but failed. Thanks a lot for any suggestions. Here is the code: last frame: id <MTLTexture> src_color; id <MTLTexture> src_depth; drawTo(src_color, src_depth); current frame: first, init a depth texture if null: id<MTLTexture> depth_texture_; if(depth_texture_) { depth_texture_ = [device_ newTextureWithDescriptor:desc]; } second， create desc for encoder: current_desc = metal_view_.currentRenderPassDescriptor; current_desc.depthAttachment.texture = depth_texture_; current_desc.depthAttachment.loadAction = MTLLoadActionClear; current_desc.depthAttachment.clearDepth = 1.0; current_desc.stencilAttachment.texture = depth_texture_; current_desc.stencilAttachment.loadAction = MTLLoadActionClear; current_desc.stencilAttachment.clearStencil = 0; current_desc.colorAttachments[0].loadAction = MTLLoadActionClear; current_desc.colorAttachments[0].clearColor = MTLClearColorMake(1.0, 1, 1, 1.0); third, blit to current MTKView: auto dst_color = current_desc.colorAttachments[0].texture; auto dst_depth = current_desc.depthAttachment.texture; id<MTLCommandBuffer> commandBuffer = [command_queue_ commandBuffer]; commandBuffer.label = @"blit"; id <MTLBlitCommandEncoder> blitEncoder = [commandBuffer blitCommandEncoder]; [blitEncoder copyFromTexture:src_color sourceSlice:0 sourceLevel:0 sourceOrigin:MTLOriginMake(srcRect.x, srcRect.y, 0) sourceSize:MTLSizeMake(srcRect.width, srcRect.height, 1) toTexture:dst_color destinationSlice:0 destinationLevel:0 destinationOrigin:MTLOriginMake(dstRect.x, dstRect.y, 0)]; [blitEncoder copyFromTexture:src_depth sourceSlice:0 sourceLevel:0 sourceOrigin:MTLOriginMake(srcRect.x, srcRect.y, 0) sourceSize:MTLSizeMake(srcRect.width, srcRect.height, 1) toTexture:dst_depth destinationSlice:0 destinationLevel:0 destinationOrigin:MTLOriginMake(dstRect.x, dstRect.y, 0)]; [blitEncoder endEncoding]; [commandBuffer commit]; [commandBuffer waitUntilCompleted];