我写了一个简单的OpenGL程序，它只是从一个角度渲染一个立方体。它非常简单：仅顶点缓冲区(无索引缓冲区)，仅将顶点乘以来自统一缓冲区的 MVP 矩阵的顶点着色器，以及仅返回红色的静态片段着色器。最近，我尝试在 Vulkan 中编写相同的程序，但我遇到了一些问题。
我首先按照英特尔无密钥 API 教程设置一个简单的 2D 纹理渲染程序，但当我进入 3D 时，我开始遇到问题。为了调试它，我简化了程序以匹配我旧的OpenGL程序(删除了纹理和我在Vulkan中所做的其他一些额外内容)，甚至使用了完全相同的顶点和MVP数据。但是，我只是无法让立方体在 Vulkan 中正确渲染。
我知道 OpenGL 坐标不会直接映射到 Vulkan 坐标，因为 Y 坐标是翻转的，但如果有什么应该把图像颠倒过来，我已经尝试在 MVP 中切换 Y 值。我觉得这里缺少一些其他细节的坐标，但我只是无法弄清楚四处搜索并查看有关将 OpenGL 代码库转换为 Vulkan 的指南。
我包括我上传到着色器的数据，以及来自 Vulkan 代码库的一些核心代码。Vulkan 代码在 D 中，因此它与 C++ 相似，但略有不同。使用我用于包装 Vulkan(爆发)的库，设备级函数被加载到设备调度中(在代码中作为 device.dispatch 访问)，当在没有 vk 前缀的调度上调用它们时，函数的设备和命令缓冲区(分配给代码中的调度)参数会自动填充。
顶点数据：
[ [1, 1, 1, 1],
[1, 1, -1, 1],
[-1, 1, -1, 1],
[1, 1, 1, 1],
[-1, 1, -1, 1],
[-1, 1, 1, 1],
[1, 1, 1, 1],
[1, -1, 1, 1],
[1, -1, -1, 1],
[1, 1, 1, 1],
[1, -1, -1, 1],
[1, 1, -1, 1],
[1, 1, -1, 1],
[1, -1, -1, 1],
[-1, -1, -1, 1],
[1, 1, -1, 1],
[-1, -1, -1, 1],
[-1, 1, -1, 1],
[-1, 1, -1, 1],
[-1, -1, -1, 1],
[-1, -1, 1, 1],
[-1, 1, -1, 1],
[-1, -1, 1, 1],
[-1, 1, 1, 1],
[-1, 1, 1, 1],
[-1, -1, 1, 1],
[1, -1, 1, 1],
[-1, 1, 1, 1],
[1, -1, 1, 1],
[1, 1, 1, 1],
[1, -1, 1, 1],
[1, -1, -1, 1],
[-1, -1, -1, 1],
[1, -1, 1, 1],
[-1, -1, -1, 1],
[-1, -1, 1, 1] ]
最有价值球员：
[ [-1.0864, -0.993682, -0.687368, -0.685994],
[0, 2.07017, 0.515526, -0.514496],
[-1.44853, 0.745262, 0.515526, 0.514496],
[-8.04095e-16, 0, 5.64243, 5.83095] ]
图形管道设置：
VkPipelineShaderStageCreateInfo[] shader_stage_infos = [
{
stage: VK_SHADER_STAGE_VERTEX_BIT,
_module: vertex_shader,
pName: "main"
},
{
stage: VK_SHADER_STAGE_FRAGMENT_BIT,
_module: fragment_shader,
pName: "main"
}
];
VkVertexInputBindingDescription[] vertex_binding_descriptions = [
{
binding: 0,
stride: VertexData.sizeof,
inputRate: VK_VERTEX_INPUT_RATE_VERTEX
}
];
VkVertexInputAttributeDescription[] vertex_attribute_descriptions = [
{
location: 0,
binding: vertex_binding_descriptions[0].binding,
format: VK_FORMAT_R32G32B32A32_SFLOAT,
offset: VertexData.x.offsetof
},
{
location: 1,
binding: vertex_binding_descriptions[0].binding,
format: VK_FORMAT_R32G32_SFLOAT,
offset: VertexData.u.offsetof
}
];
VkPipelineVertexInputStateCreateInfo vertex_input_state_info = {
vertexBindingDescriptionCount: vertex_binding_descriptions.length.to!uint,
pVertexBindingDescriptions: vertex_binding_descriptions.ptr,
vertexAttributeDescriptionCount: vertex_attribute_descriptions.length.to!uint,
pVertexAttributeDescriptions: vertex_attribute_descriptions.ptr
};
VkPipelineInputAssemblyStateCreateInfo input_assembly_state_info = {
topology: VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST,
primitiveRestartEnable: VK_FALSE
};
VkPipelineViewportStateCreateInfo viewport_state_info = {
viewportCount: 1,
pViewports: null,
scissorCount: 1,
pScissors: null
};
VkPipelineRasterizationStateCreateInfo rasterization_state_info = {
depthBiasClamp: 0.0,
polygonMode: VK_POLYGON_MODE_FILL,
cullMode: VK_CULL_MODE_FRONT_AND_BACK,
frontFace: VK_FRONT_FACE_COUNTER_CLOCKWISE,
lineWidth: 1
};
VkPipelineMultisampleStateCreateInfo multisample_state_info = {
rasterizationSamples: VK_SAMPLE_COUNT_1_BIT,
minSampleShading: 1
};
VkPipelineColorBlendAttachmentState[] color_blend_attachment_states = [
{
blendEnable: VK_FALSE,
srcColorBlendFactor: VK_BLEND_FACTOR_ONE,
dstColorBlendFactor: VK_BLEND_FACTOR_ZERO,
colorBlendOp: VK_BLEND_OP_ADD,
srcAlphaBlendFactor: VK_BLEND_FACTOR_ONE,
dstAlphaBlendFactor: VK_BLEND_FACTOR_ZERO,
alphaBlendOp: VK_BLEND_OP_ADD,
colorWriteMask:
VK_COLOR_COMPONENT_R_BIT |
VK_COLOR_COMPONENT_G_BIT |
VK_COLOR_COMPONENT_B_BIT |
VK_COLOR_COMPONENT_A_BIT
}
];
VkPipelineColorBlendStateCreateInfo color_blend_state_info = {
logicOpEnable: VK_FALSE,
logicOp: VK_LOGIC_OP_COPY,
attachmentCount: color_blend_attachment_states.length.to!uint,
pAttachments: color_blend_attachment_states.ptr,
blendConstants: [ 0, 0, 0, 0 ]
};
VkDynamicState[] dynamic_states = [
VK_DYNAMIC_STATE_VIEWPORT,
VK_DYNAMIC_STATE_SCISSOR
];
VkPipelineDynamicStateCreateInfo dynamic_state_info = {
dynamicStateCount: dynamic_states.length.to!uint,
pDynamicStates: dynamic_states.ptr
};
VkGraphicsPipelineCreateInfo pipeline_info = {
stageCount: shader_stage_infos.length.to!uint,
pStages: shader_stage_infos.ptr,
pVertexInputState: &vertex_input_state_info,
pInputAssemblyState: &input_assembly_state_info,
pTessellationState: null,
pViewportState: &viewport_state_info,
pRasterizationState: &rasterization_state_info,
pMultisampleState: &multisample_state_info,
pDepthStencilState: null,
pColorBlendState: &color_blend_state_info,
pDynamicState: &dynamic_state_info,
layout: pipeline_layout,
renderPass: render_pass,
subpass: 0,
basePipelineHandle: VK_NULL_HANDLE,
basePipelineIndex: -1
};
VkPipeline[1] pipelines;
checkVk(device.dispatch.CreateGraphicsPipelines(VK_NULL_HANDLE, 1, [pipeline_info].ptr, pipelines.ptr));
pipeline = pipelines[0];
绘图：
if(device.dispatch.WaitForFences(1, [fence].ptr, VK_FALSE, 1000000000) != VK_SUCCESS)
throw new StringException("timed out waiting for fence");
device.dispatch.ResetFences(1, [fence].ptr);
uint image_index;
switch(device.dispatch.AcquireNextImageKHR(swapchain.swapchain, uint64_t.max, image_available_semaphore, VK_NULL_HANDLE, &image_index)) {
case VK_SUCCESS:
case VK_SUBOPTIMAL_KHR:
break;
case VK_ERROR_OUT_OF_DATE_KHR:
on_window_size_changed();
break;
default:
throw new StringException("unhandled vk result on swapchain image acquisition");
}
if(framebuffer != VK_NULL_HANDLE) device.dispatch.DestroyFramebuffer(framebuffer);
VkFramebufferCreateInfo framebuffer_info = {
renderPass: swapchain.render_pass,
attachmentCount: 1,
pAttachments: [swapchain.image_resources[image_index].image_view].ptr,
width: swapchain.extent.width,
height: swapchain.extent.height,
layers: 1
};
checkVk(device.dispatch.CreateFramebuffer(&framebuffer_info, &framebuffer));
VkCommandBufferBeginInfo cmd_begin_info = { flags: VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT };
VkImageSubresourceRange image_subresource_range = {
aspectMask: VK_IMAGE_ASPECT_COLOR_BIT,
baseMipLevel: 0,
levelCount: 1,
baseArrayLayer: 0,
layerCount: 1,
};
VkImageMemoryBarrier barrier_from_present_to_draw = {
srcAccessMask: VK_ACCESS_MEMORY_READ_BIT,
dstAccessMask: VK_ACCESS_MEMORY_READ_BIT,
oldLayout: VK_IMAGE_LAYOUT_PRESENT_SRC_KHR,
newLayout: VK_IMAGE_LAYOUT_PRESENT_SRC_KHR,
srcQueueFamilyIndex: device.present_queue.family_index,
dstQueueFamilyIndex: device.graphics_queue.family_index,
image: swapchain.image_resources[image_index].image,
subresourceRange: image_subresource_range
};
VkImageMemoryBarrier barrier_from_draw_to_present = {
srcAccessMask: VK_ACCESS_MEMORY_READ_BIT,
dstAccessMask: VK_ACCESS_MEMORY_READ_BIT,
oldLayout: VK_IMAGE_LAYOUT_PRESENT_SRC_KHR,
newLayout: VK_IMAGE_LAYOUT_PRESENT_SRC_KHR,
srcQueueFamilyIndex: device.graphics_queue.family_index,
dstQueueFamilyIndex: device.present_queue.family_index,
image: swapchain.image_resources[image_index].image,
subresourceRange: image_subresource_range
};
VkViewport viewport = {
x: 0,
y: 0,
width: swapchain.extent.width,
height: swapchain.extent.height,
minDepth: 0,
maxDepth: 1
};
VkRect2D scissor = {
offset: {
x: 0,
y: 0
},
extent: swapchain.extent
};
VkClearValue[] clear_values = [
{ color: { [ 1.0, 0.8, 0.4, 0.0 ] } }
];
VkRenderPassBeginInfo render_pass_begin_info = {
renderPass: swapchain.render_pass,
framebuffer: framebuffer,
renderArea: {
offset: {
x: 0,
y: 0
},
extent: swapchain.extent
},
clearValueCount: clear_values.length.to!uint,
pClearValues: clear_values.ptr
};
device.dispatch.commandBuffer = command_buffer;
device.dispatch.BeginCommandBuffer(&cmd_begin_info);
if(device.graphics_queue.handle != device.present_queue.handle)
device.dispatch.CmdPipelineBarrier(
VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT,
VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT,
0, 0, null, 0, null, 1,
&barrier_from_present_to_draw
);
device.dispatch.CmdBeginRenderPass(&render_pass_begin_info, VK_SUBPASS_CONTENTS_INLINE);
device.dispatch.CmdBindPipeline(VK_PIPELINE_BIND_POINT_GRAPHICS, swapchain.pipeline);
device.dispatch.CmdSetViewport(0, 1, &viewport);
device.dispatch.CmdSetScissor(0, 1, &scissor);
const(ulong) vertex_buffer_offset = 0;
device.dispatch.CmdBindVertexBuffers(0, 1, &vertex_buffer, &vertex_buffer_offset);
device.dispatch.CmdBindDescriptorSets(VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline_layout, 0, 1, &descriptor_set, 0, null);
device.dispatch.CmdDraw(draw_count, 1, 0, 0);
device.dispatch.CmdEndRenderPass();
if(device.graphics_queue.handle != device.present_queue.handle)
device.dispatch.CmdPipelineBarrier(
VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT,
VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT,
0, 0, null, 0, null, 1,
&barrier_from_draw_to_present
);
checkVk(device.dispatch.EndCommandBuffer());
device.dispatch.commandBuffer = VK_NULL_HANDLE;
VkSubmitInfo submit_info = {
waitSemaphoreCount: 1,
pWaitSemaphores: [image_available_semaphore].ptr,
pWaitDstStageMask: castFrom!(VkPipelineStageFlagBits*).to!(const(uint)*)([VK_PIPELINE_STAGE_TRANSFER_BIT].ptr),
commandBufferCount: 1,
pCommandBuffers: [command_buffer].ptr,
signalSemaphoreCount: 1,
pSignalSemaphores: [rendering_finished_semaphore].ptr
};
checkVk(device.dispatch.vkQueueSubmit(device.graphics_queue.handle, 1, [submit_info].ptr, fence));
VkPresentInfoKHR present_info = {
waitSemaphoreCount: 1,
pWaitSemaphores: [rendering_finished_semaphore].ptr,
swapchainCount: 1,
pSwapchains: [swapchain.swapchain].ptr,
pImageIndices: [image_index].ptr
};
switch(device.dispatch.vkQueuePresentKHR(device.present_queue.handle, &present_info)) {
case VK_SUCCESS:
break;
case VK_ERROR_OUT_OF_DATE_KHR:
case VK_SUBOPTIMAL_KHR:
on_window_size_changed();
break;
default:
throw new StringException("unhandled vk result on presentation");
}
(我无法嵌入图像，因为我的重复太低，抱歉)
程序输出：
OpenGL 按预期绘制立方体 OpenGL 输出
Vulkan除了清晰的颜色外，不会渲染任何东西。
更新：
通过将剔除模式更改为 VK_CULL_MODE_NONE 来修复剔除模式后，这是我得到的结果： 剔除模式修复后的输出
VK_CULL_MODE_FRONT_AND_BACK
我认为这是你的问题:)
剔除模式修复后，似乎您的顶点数据布局中存在问题。Vulkan 期望(根据您的布局绑定)类似
struct Vertex {
vec4 x;
vec2 u;
};
Vertex VertexData[] = {...};
因为您在vertex_binding_descriptions.inputRate字段中设置了VK_VERTEX_INPUT_RATE_VERTEX。
似乎在您的情况下，您应该VK_VERTEX_INPUT_RATE_INSTANCE设置为彼此之后使用缓冲区。
修复：看到您的新评论，看起来我误解了您的顶点布局，所以它无济于事。