\u6458\u8981：\u672c\u7ae0\u7cfb\u7edf\u4ecb\u7ecd\u4e86\u5728 VulkanSceneGraph (VSG) \u4e2d\u52a0\u8f7d\u5916\u90e8 3D \u6a21\u578b\u7684\u6838\u5fc3\u6d41\u7a0b\u3002\u91cd\u70b9\u9610\u8ff0\u4e86\u5982\u4f55\u4f7f\u7528\u7edf\u4e00\u7684 vsg::read() \u51fd\u6570\u52a0\u8f7d glTF\/OBJ \u7b49\u683c\u5f0f\u7684\u6a21\u578b，\u5f3a\u8c03\u4e86 vsgXchange \u7ec4\u4ef6\u5e93\u5728\u63d0\u4f9b\u683c\u5f0f\u652f\u6301\u4e2d\u7684\u5173\u952e\u4f5c\u7528，\u5e76\u8be6\u7ec6\u8bf4\u660e\u4e86 CMake \u7684\u94fe\u63a5\u914d\u7f6e\u65b9\u6cd5\u3002\u6b64\u5916，\u672c\u7ae0\u8fd8\u89e3\u91ca\u4e86\u52a0\u8f7d\u540e\u5f97\u5230\u7684 Node \u5b50\u6811\u7ed3\u6784\u3001\u5982\u4f55\u901a\u8fc7 vsg::Options \u63a7\u5236\u52a0\u8f7d\u884c\u4e3a（\u5982\u5750\u6807\u8f74\u8f6c\u6362\u548c\u8d44\u6e90\u8def\u5f84），\u5e76\u63d0\u4f9b\u4e86\u4e00\u4e2a\u5b8c\u6574\u7684\u6a21\u578b\u67e5\u770b\u5668\u793a\u4f8b\u3002\u6700\u540e，\u603b\u7ed3\u4e86\u5e38\u89c1\u95ee\u9898\u7684\u6392\u67e5\u601d\u8def，\u4e3a\u540e\u7eed\u7684\u6a21\u578b\u53d8\u6362\u3001\u52a8\u753b\u548c\u7eb9\u7406\u5b66\u4e60\u5960\u5b9a\u4e86\u57fa\u7840\u3002<\/p>\n
\u672c\u7ae0\u5b9a\u4f4d：\u5b9e\u9645\u9879\u76ee\u5f88\u5c11\u624b\u6413\u51e0\u4f55\u4f53\u2014\u2014vsgXchange \u7ec4\u4ef6\u5e93\u8ba9 vsg::read() \u76f4\u63a5\u5403 glTF \/ OBJ \/ \u56fe\u50cf \/ \u5b57\u4f53\u3002\u672c\u7ae0\u8bb2\u6e05\u300c\u4e00\u884c\u8bfb\u53d6\u3001\u6302\u5165\u573a\u666f\u56fe\u300d\u3002<\/p>\n
VSG \u7684 IO \u7cfb\u7edf\u6709\u4e00\u4e2a\u7edf\u4e00\u8bfb\u53d6\u51fd\u6570（\u4f4d\u4e8e vsg\/io\/read.h）：<\/p>\n
ref_ptr<Object> read(const Path& filename, ref_ptr<const Options> options = {});<\/p>\n
\u5b83\u6839\u636e\u6587\u4ef6\u6269\u5c55\u540d\u6311\u9009\u5df2\u6ce8\u518c\u7684 ReaderWriter\u3002vsgXchange \u5728\u94fe\u63a5\u540e\u81ea\u52a8\u6ce8\u518c\u5bf9 glTF\/OBJ\/KTX2\/PNG\/\u5b57\u4f53\u7b49\u7684\u652f\u6301\u3002<\/p>\n
\/\/ \u8bfb\u53d6 glTF（vsgXchange \u63d0\u4f9b\u652f\u6301）
\nauto object = vsg::read("models\/duck.gltf");
\nif (!object)
\n{
\n std::cerr << "\u52a0\u8f7d\u5931\u8d25：\u8bf7\u786e\u8ba4\u6587\u4ef6\u5b58\u5728\u4e14\u5df2\u94fe\u63a5 vsgXchange" << std::endl;
\n return 1;
\n}
\nauto model = vsg::ref_ptr<vsg::Node>(object); \/\/ \u8f6c\u6362\u4e3a Node \u5e76\u6302\u5165\u573a\u666f\u56fe
\nroot->addChild(model);<\/p>\n
\u26a0\ufe0f \u5fc5\u987b\u94fe\u63a5 vsgXchange：\u6838\u5fc3\u5e93 vsg \u53ea\u8ba4\u81ea\u5bb6\u7684 .vsgt\/.vsgb \u7b49\u683c\u5f0f；glTF\/OBJ\/PNG \u5168\u9760 vsgXchange\u3002\u6ca1\u88c5\u5b83，vsg::read("x.gltf") \u4f1a\u8fd4\u56de null\u3002<\/p>\n
find_package(vsg REQUIRED)
\nfind_package(vsgXchange REQUIRED) # \u989d\u5916\u5f15\u5165\u6a21\u578b\/\u56fe\u50cf\u652f\u6301<\/p>\n
target_link_libraries(my_app PRIVATE vsg::vsg vsgXchange::vsgXchange)<\/p>\n
vsgXchange \u4f1a\u6309\u9700\u62c9\u5165 tinygltf\u3001libpng\u3001ktx \u7b49\u5e95\u5c42\u4f9d\u8d56（\u591a\u6570\u901a\u8fc7 FetchContent \u81ea\u52a8\u5904\u7406）\u3002<\/p>\n
vsgXchange \u7684 glTF \u8bfb\u53d6\u5668\u4f1a\u628a\u6587\u4ef6\u89e3\u6790\u6210\u4e00\u68f5\u5b8c\u6574\u7684 Node \u5b50\u6811：<\/p>\n
\u4e5f\u5c31\u662f\u8bf4，\u4f60\u62ff\u5230\u7684\u5df2\u7ecf\u662f\u300c\u53ef\u6e32\u67d3\u300d\u7684\u573a\u666f\u56fe，\u901a\u5e38\u53ea\u9700\u5957\u4e00\u5c42 MatrixTransform \u8c03\u6574\u4f4d\u7f6e\/\u7f29\u653e\u5373\u53ef\u3002<\/p>\n
\u9700\u8981\u5750\u6807\u7cfb\u8f6c\u6362（glTF \u662f Y-up，VSG \u5e38 Z-up）\u3001\u7f29\u653e\u3001\u6216\u6307\u5b9a\u5b57\u4f53\/\u56fe\u50cf\u641c\u7d22\u8def\u5f84\u65f6，\u4f20 Options：<\/p>\n
auto options = vsg::Options::create();
\noptions->paths = vsg::Paths{"models\/", "textures\/"}; \/\/ \u8d44\u6e90\u641c\u7d22\u8def\u5f84
\noptions->fileCache = vsg::getFileCache(); \/\/ \u5171\u4eab\u5df2\u52a0\u8f7d\u5bf9\u8c61
\nauto model = vsg::read("duck.gltf", options);<\/p>\n
glTF \u4e0e VSG \u7684\u5750\u6807\u8f74\u5dee\u5f02\u901a\u5e38\u7531 vsgXchange \u5728\u8bfb\u53d6\u65f6\u6309 options \u5904\u7406；\u9047\u5230\u6a21\u578b\u300c\u8eba\u5e73\u300d，\u591a\u534a\u662f up-axis \u6ca1\u8bbe\u5bf9，\u68c0\u67e5 Options \u7684\u8f74\u5411\/\u7f29\u653e\u8bbe\u7f6e\u3002<\/p>\n
\u4e0b\u9762\u662f\u4e00\u4e2a\u5b8c\u6574\u7684\u3001\u53ef\u76f4\u63a5\u7f16\u8bd1\u8fd0\u884c\u7684 VSG \u7a0b\u5e8f\u793a\u4f8b，\u6f14\u793a\u5982\u4f55\u52a0\u8f7d glTF \u6a21\u578b\u5e76\u521b\u5efa\u4e00\u4e2a\u7b80\u5355\u7684\u67e5\u770b\u5668\u3002<\/p>\n
#include <vsg\/all.h>
\n#include <iostream><\/p>\n
int main(int argc, char** argv)
\n{
\n \/\/ 1. \u89e3\u6790\u547d\u4ee4\u884c\u53c2\u6570（\u6a21\u578b\u6587\u4ef6\u8def\u5f84）
\n vsg::CommandLine arguments(&argc, argv);
\n auto modelFile = arguments.value(std::string("models\/duck.gltf"), "–model");
\n auto width = arguments.value(1024, "–width");
\n auto height = arguments.value(768, "–height");<\/p>\n
\/\/ 2. \u521b\u5efa\u7a97\u53e3\u548c\u67e5\u770b\u5668
\n auto traits = vsg::WindowTraits::create();
\n traits->width = width;
\n traits->height = height;
\n traits->title = "VSG Model Viewer";
\n auto window = vsg::Window::create(traits);
\n if (!window)
\n {
\n std::cerr << "\u65e0\u6cd5\u521b\u5efa\u7a97\u53e3" << std::endl;
\n return 1;
\n }<\/p>\n
auto viewer = vsg::Viewer::create();
\n viewer->addWindow(window);<\/p>\n
\/\/ 3. \u52a0\u8f7d\u6a21\u578b（\u9700\u8981\u5df2\u94fe\u63a5 vsgXchange）
\n auto options = vsg::Options::create();
\n options->paths = vsg::getEnvPaths("VSG_FILE_PATH"); \/\/ \u4ece\u73af\u5883\u53d8\u91cf\u83b7\u53d6\u641c\u7d22\u8def\u5f84
\n options->paths.push_back("models\/"); \/\/ \u6dfb\u52a0\u672c\u5730\u6a21\u578b\u76ee\u5f55
\n options->paths.push_back("textures\/"); \/\/ \u6dfb\u52a0\u7eb9\u7406\u76ee\u5f55<\/p>\n
auto model = vsg::read<vsg::Node>(modelFile, options);
\n if (!model)
\n {
\n std::cerr << "\u6a21\u578b\u52a0\u8f7d\u5931\u8d25: " << modelFile << std::endl;
\n std::cerr << "\u8bf7\u786e\u8ba4：" << std::endl;
\n std::cerr << " 1. \u6587\u4ef6\u8def\u5f84\u6b63\u786e" << std::endl;
\n std::cerr << " 2. \u5df2\u5b89\u88c5\u5e76\u94fe\u63a5 vsgXchange" << std::endl;
\n std::cerr << " 3. \u4f9d\u8d56\u7684\u7eb9\u7406\u6587\u4ef6\u5728\u641c\u7d22\u8def\u5f84\u4e2d" << std::endl;
\n return 1;
\n }<\/p>\n
\/\/ 4. \u521b\u5efa\u573a\u666f\u56fe\u6839\u8282\u70b9
\n auto root = vsg::Group::create();<\/p>\n
\/\/ 5. \u6dfb\u52a0\u53d8\u6362\u8282\u70b9\u8c03\u6574\u6a21\u578b\u4f4d\u7f6e\u548c\u5927\u5c0f
\n auto transform = vsg::MatrixTransform::create();
\n \/\/ \u5c06\u6a21\u578b\u5c45\u4e2d\u5e76\u9002\u5f53\u7f29\u653e
\n transform->matrix = vsg::translate(0.0, 0.0, 0.0) * vsg::scale(0.5, 0.5, 0.5);
\n transform->addChild(model);
\n root->addChild(transform);<\/p>\n
\/\/ 6. \u8bbe\u7f6e\u76f8\u673a
\n auto camera = vsg::Camera::create();<\/p>\n
\/\/ \u900f\u89c6\u6295\u5f71
\n double aspect = static_cast<double>(width) \/ static_cast<double>(height);
\n camera->projectionMatrix = vsg::Perspective::create(60.0, aspect, 0.1, 100.0);<\/p>\n
\/\/ \u89c2\u5bdf\u77e9\u9635：\u76f8\u673a\u5728 (0, 2, 5)，\u770b\u5411\u539f\u70b9，\u4e0a\u65b9\u5411\u4e3a Y \u8f74
\n camera->viewMatrix = vsg::LookAt::create(
\n vsg::dvec3(0.0, 2.0, 5.0), \/\/ \u76f8\u673a\u4f4d\u7f6e
\n vsg::dvec3(0.0, 0.0, 0.0), \/\/ \u89c2\u5bdf\u76ee\u6807
\n vsg::dvec3(0.0, 1.0, 0.0) \/\/ \u4e0a\u65b9\u5411
\n );<\/p>\n
\/\/ \u89c6\u53e3\u4e0e\u7a97\u53e3\u5927\u5c0f\u4e00\u81f4
\n camera->viewportState = vsg::ViewportState::create(window->extent2D());<\/p>\n
\/\/ 7. \u521b\u5efa\u6e32\u67d3\u56fe\u548c\u547d\u4ee4\u56fe
\n auto renderGraph = vsg::createRenderGraphForView(window, camera, root);
\n auto commandGraph = vsg::createCommandGraphForView(window, camera, root);<\/p>\n
\/\/ 8. \u914d\u7f6e\u67e5\u770b\u5668
\n viewer->assignRecordAndSubmitTaskAndPresentation({commandGraph});<\/p>\n
\/\/ 9. \u7f16\u8bd1\u573a\u666f\u56fe
\n auto compileResult = viewer->compile();
\n if (!compileResult)
\n {
\n std::cerr << "\u573a\u666f\u56fe\u7f16\u8bd1\u5931\u8d25" << std::endl;
\n return 1;
\n }<\/p>\n
\/\/ 10. \u6dfb\u52a0\u8f68\u9053\u76f8\u673a\u63a7\u5236\u5668（\u65b9\u4fbf\u4ea4\u4e92\u67e5\u770b）
\n auto trackball = vsg::Trackball::create(camera, window);
\n viewer->addEventHandler(trackball);<\/p>\n
\/\/ 11. \u4e3b\u6e32\u67d3\u5faa\u73af
\n std::cout << "\u6210\u529f\u52a0\u8f7d\u6a21\u578b: " << modelFile << std::endl;
\n std::cout << "\u6309 ESC \u952e\u9000\u51fa\u7a0b\u5e8f" << std::endl;<\/p>\n
while (viewer->advanceToNextFrame())
\n {
\n \/\/ \u5904\u7406\u7a97\u53e3\u4e8b\u4ef6（\u9f20\u6807\u3001\u952e\u76d8\u7b49）
\n viewer->handleEvents();<\/p>\n
\/\/ \u66f4\u65b0\u573a\u666f（\u52a8\u753b\u3001\u76f8\u673a\u7b49）
\n viewer->update();<\/p>\n
\/\/ \u8bb0\u5f55\u547d\u4ee4\u7f13\u51b2\u533a\u5e76\u63d0\u4ea4
\n viewer->recordAndSubmit();<\/p>\n
\/\/ \u5448\u73b0\u5230\u5c4f\u5e55
\n viewer->present();
\n }<\/p>\n
return 0;
\n}<\/p>\n
\u786e\u4fdd\u4f60\u7684 CMakeLists.txt \u6b63\u786e\u94fe\u63a5\u4e86 vsgXchange：<\/p>\n
cmake_minimum_required(VERSION 3.12)
\nproject(model_viewer)<\/p>\n
find_package(vsg REQUIRED)
\nfind_package(vsgXchange REQUIRED) # \u5173\u952e：\u5f15\u5165\u6a21\u578b\/\u56fe\u50cf\u652f\u6301<\/p>\n
add_executable(model_viewer main.cpp)
\ntarget_link_libraries(model_viewer PRIVATE
\n vsg::vsg
\n vsgXchange::vsgXchange # \u5173\u952e：\u94fe\u63a5 vsgXchange
\n)<\/p>\n
mkdir build && cd build
\ncmake .. -DCMAKE_PREFIX_PATH=\/path\/to\/vsg\/install
\nmake\n<\/li>\n
.\/model_viewer –model models\/duck.gltf –width 1280 –height 720\n<\/li>\n
\u63d0\u793a：\u5982\u679c\u6a21\u578b\u663e\u793a\u5f02\u5e38（\u5982\u98a0\u5012\u3001\u5927\u5c0f\u4e0d\u5408\u9002），\u53ef\u4ee5\u8c03\u6574 transform->matrix \u4e2d\u7684\u53d8\u6362\u53c2\u6570，\u6216\u5728 Options \u4e2d\u8bbe\u7f6e upAxis \u548c scale\u3002<\/p>\n
| vsg::read \u8fd4\u56de null<\/td>\n | \u672a\u94fe\u63a5 vsgXchange \u6216\u6587\u4ef6\/\u8def\u5f84\u9519\u8bef<\/td>\n | \u786e\u8ba4 target_link_libraries(… vsgXchange::vsgXchange)；\u68c0\u67e5\u8def\u5f84<\/td>\n<\/tr>\n |
| \u6a21\u578b\u98a0\u5012\/\u8eba\u5e73<\/td>\n | up-axis \/ \u7f29\u653e\u8bbe\u7f6e\u4e0d\u6b63\u786e<\/td>\n | \u5728 Options \u4e2d\u8bbe\u7f6e\u8f74\u5411\u4e0e\u7f29\u653e，\u6216\u4f7f\u7528\u5916\u5c42 MatrixTransform \u65cb\u8f6c<\/td>\n<\/tr>\n |
| \u7eb9\u7406\u4e22\u5931<\/td>\n | \u7eb9\u7406\u6587\u4ef6\u4e0d\u5728\u641c\u7d22\u8def\u5f84\u4e2d<\/td>\n | \u4f7f\u7528 Options::paths \u6307\u5b9a\u8d44\u6e90\u76ee\u5f55<\/td>\n<\/tr>\n |
| \u7f16\u8bd1\u62a5\u627e\u4e0d\u5230 glTF \u7b26\u53f7<\/td>\n | \u53ea\u5b89\u88c5\u4e86\u6838\u5fc3\u5e93<\/td>\n | \u5b89\u88c5\u5e76\u94fe\u63a5 vsgXchange<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n 13.9 \u6027\u80fd\u4f18\u5316\u4e0e\u9ad8\u7ea7\u7528\u6cd5<\/h3>\n\u5728\u638c\u63e1\u4e86\u57fa\u7840\u52a0\u8f7d\u6d41\u7a0b\u540e，\u4e86\u89e3\u4e00\u4e9b\u9ad8\u7ea7\u7528\u6cd5\u548c\u6027\u80fd\u4f18\u5316\u6280\u5de7\u80fd\u8ba9\u4f60\u5728\u590d\u6742\u9879\u76ee\u4e2d\u66f4\u9ad8\u6548\u5730\u4f7f\u7528 VSG \u7684\u6a21\u578b\u52a0\u8f7d\u529f\u80fd\u3002<\/p>\n 1. \u8d44\u6e90\u590d\u7528：\u907f\u514d\u91cd\u590d\u52a0\u8f7d<\/h4>\n\u5f53\u591a\u4e2a\u573a\u666f\u9700\u8981\u52a0\u8f7d\u540c\u4e00\u6a21\u578b\u6216\u7eb9\u7406\u65f6，\u91cd\u590d\u4ece\u78c1\u76d8\u8bfb\u53d6\u4f1a\u6d6a\u8d39 I\/O \u548c\u5185\u5b58\u3002VSG \u63d0\u4f9b\u4e86\u4e24\u79cd\u8d44\u6e90\u590d\u7528\u673a\u5236：<\/p>\n \u4f7f\u7528 vsg::SharedObjects \u5168\u5c40\u5171\u4eab<\/h5>\n\/\/ \u521b\u5efa\u5168\u5c40\u5171\u4eab\u5bf9\u8c61\u7ba1\u7406\u5668 \/\/ \u7b2c\u4e00\u6b21\u52a0\u8f7d\u65f6\u6ce8\u518c\u5230\u5171\u4eab\u7ba1\u7406\u5668 \/\/ \u540e\u7eed\u52a0\u8f7d\u76f8\u540c\u6587\u4ef6\u65f6，\u76f4\u63a5\u4ece\u5171\u4eab\u7ba1\u7406\u5668\u83b7\u53d6 \u4f7f\u7528 Options::fileCache \u6587\u4ef6\u7ea7\u7f13\u5b58<\/h5>\n\/\/ \u521b\u5efa\u5e26\u6587\u4ef6\u7f13\u5b58\u7684 Options \/\/ \u591a\u6b21\u8bfb\u53d6\u540c\u4e00\u6587\u4ef6，\u53ea\u6709\u7b2c\u4e00\u6b21\u4f1a\u771f\u6b63\u4ece\u78c1\u76d8\u52a0\u8f7d \u9002\u7528\u573a\u666f：<\/p>\n
|