# <hr>Calculates the tangents and bitangents for the imported meshes. # # Does nothing if a mesh does not have normals. You might want this post # processing step to be executed if you plan to use tangent space calculations # such as normal mapping applied to the meshes. There's a config setting, # <tt>#AI_CONFIG_PP_CT_MAX_SMOOTHING_ANGLE<tt>, which allows you to specify # a maximum smoothing angle for the algorithm. However, usually you'll # want to leave it at the default value. # aiProcess_CalcTangentSpace = 0x1 ## <hr>Identifies and joins identical vertex data sets within all # imported meshes. # # After this step is run, each mesh contains unique vertices, # so a vertex may be used by multiple faces. You usually want # to use this post processing step. If your application deals with # indexed geometry, this step is compulsory or you'll just waste rendering # time. <b>If this flag is not specified<b>, no vertices are referenced by # more than one face and <b>no index buffer is required<b> for rendering. # aiProcess_JoinIdenticalVertices = 0x2 ## <hr>Converts all the imported data to a left-handed coordinate space. # # By default the data is returned in a right-handed coordinate space (which # OpenGL prefers). In this space, +X points to the right, # +Z points towards the viewer, and +Y points upwards. In the DirectX # coordinate space +X points to the right, +Y points upwards, and +Z points # away from the viewer. # # You'll probably want to consider this flag if you use Direct3D for # rendering. The #aiProcess_ConvertToLeftHanded flag supersedes this # setting and bundles all conversions typically required for D3D-based # applications. # aiProcess_MakeLeftHanded = 0x4 ## <hr>Triangulates all faces of all meshes. # # By default the imported mesh data might contain faces with more than 3 # indices. For rendering you'll usually want all faces to be triangles. # This post processing step splits up faces with more than 3 indices into # triangles. Line and point primitives are #not# modified! If you want # 'triangles only' with no other kinds of primitives, try the following # solution: # <ul> # <li>Specify both #aiProcess_Triangulate and #aiProcess_SortByPType <li> # <li>Ignore all point and line meshes when you process assimp's output<li> # <ul> # aiProcess_Triangulate = 0x8 ## <hr>Removes some parts of the data structure (animations, materials, # light sources, cameras, textures, vertex components). # # The components to be removed are specified in a separate # configuration option, <tt>#AI_CONFIG_PP_RVC_FLAGS<tt>. This is quite useful # if you don't need all parts of the output structure. Vertex colors # are rarely used today for example... Calling this step to remove unneeded # data from the pipeline as early as possible results in increased # performance and a more optimized output data structure. # This step is also useful if you want to force Assimp to recompute # normals or tangents. The corresponding steps don't recompute them if # they're already there (loaded from the source asset). By using this # step you can make sure they are NOT there. # # This flag is a poor one, mainly because its purpose is usually # misunderstood. Consider the following case: a 3D model has been exported # from a CAD app, and it has per-face vertex colors. Vertex positions can't be # shared, thus the #aiProcess_JoinIdenticalVertices step fails to # optimize the data because of these nasty little vertex colors. # Most apps don't even process them, so it's all for nothing. By using # this step, unneeded components are excluded as early as possible # thus opening more room for internal optimizations. # aiProcess_RemoveComponent = 0x10 ## <hr>Generates normals for all faces of all meshes. # # This is ignored if normals are already there at the time this flag # is evaluated. Model importers try to load them from the source file, so # they're usually already there. Face normals are shared between all points # of a single face, so a single point can have multiple normals, which # forces the library to duplicate vertices in some cases. # #aiProcess_JoinIdenticalVertices is #senseless# then. # # This flag may not be specified together with #aiProcess_GenSmoothNormals. # aiProcess_GenNormals = 0x20 ## <hr>Generates smooth normals for all vertices in the mesh. # # This is ignored if normals are already there at the time this flag # is evaluated. Model importers try to load them from the source file, so # they're usually already there. # # This flag may not be specified together with # #aiProcess_GenNormals. There's a configuration option, # <tt>#AI_CONFIG_PP_GSN_MAX_SMOOTHING_ANGLE<tt> which allows you to specify # an angle maximum for the normal smoothing algorithm. Normals exceeding # this limit are not smoothed, resulting in a 'hard' seam between two faces. # Using a decent angle here (e.g. 80 degrees) results in very good visual # appearance. # aiProcess_GenSmoothNormals = 0x40 ## <hr>Splits large meshes into smaller sub-meshes. # # This is quite useful for real-time rendering, where the number of triangles # which can be maximally processed in a single draw-call is limited # by the video driverhardware. The maximum vertex buffer is usually limited # too. Both requirements can be met with this step: you may specify both a # triangle and vertex limit for a single mesh. # # The split limits can (and should!) be set through the # <tt>#AI_CONFIG_PP_SLM_VERTEX_LIMIT<tt> and <tt>#AI_CONFIG_PP_SLM_TRIANGLE_LIMIT<tt> # settings. The default values are <tt>#AI_SLM_DEFAULT_MAX_VERTICES<tt> and # <tt>#AI_SLM_DEFAULT_MAX_TRIANGLES<tt>. # # Note that splitting is generally a time-consuming task, but only if there's # something to split. The use of this step is recommended for most users. # aiProcess_SplitLargeMeshes = 0x80 ## <hr>Removes the node graph and pre-transforms all vertices with # the local transformation matrices of their nodes. # # The output scene still contains nodes, however there is only a # root node with children, each one referencing only one mesh, # and each mesh referencing one material. For rendering, you can # simply render all meshes in order - you don't need to pay # attention to local transformations and the node hierarchy. # Animations are removed during this step. # This step is intended for applications without a scenegraph. # The step CAN cause some problems: if e.g. a mesh of the asset # contains normals and another, using the same material index, does not, # they will be brought together, but the first meshes's part of # the normal list is zeroed. However, these artifacts are rare. # @note The <tt>#AI_CONFIG_PP_PTV_NORMALIZE<tt> configuration property # can be set to normalize the scene's spatial dimension to the -1...1 # range. # aiProcess_PreTransformVertices = 0x100 ## <hr>Limits the number of bones simultaneously affecting a single vertex # to a maximum value. # # If any vertex is affected by more than the maximum number of bones, the least # important vertex weights are removed and the remaining vertex weights are # renormalized so that the weights still sum up to 1. # The default bone weight limit is 4 (defined as <tt>#AI_LMW_MAX_WEIGHTS<tt> in # config.h), but you can use the <tt>#AI_CONFIG_PP_LBW_MAX_WEIGHTS<tt> setting to # supply your own limit to the post processing step. # # If you intend to perform the skinning in hardware, this post processing # step might be of interest to you. # aiProcess_LimitBoneWeights = 0x200 ## <hr>Validates the imported scene data structure. # This makes sure that all indices are valid, all animations and # bones are linked correctly, all material references are correct .. etc. # # It is recommended that you capture Assimp's log output if you use this flag, # so you can easily find out what's wrong if a file fails the # validation. The validator is quite strict and will find #all# # inconsistencies in the data structure... It is recommended that plugin # developers use it to debug their loaders. There are two types of # validation failures: # <ul> # <li>Error: There's something wrong with the imported data. Further # postprocessing is not possible and the data is not usable at all. # The import fails. #Importer::GetErrorString() or #aiGetErrorString() # carry the error message around.<li> # <li>Warning: There are some minor issues (e.g. 1000000 animation # keyframes with the same time), but further postprocessing and use # of the data structure is still safe. Warning details are written # to the log file, <tt>#AI_SCENE_FLAGS_VALIDATION_WARNING<tt> is set # in #aiScene::mFlags<li> # <ul> # # This post-processing step is not time-consuming. Its use is not # compulsory, but recommended. # aiProcess_ValidateDataStructure = 0x400 ## <hr>Reorders triangles for better vertex cache locality. # # The step tries to improve the ACMR (average post-transform vertex cache # miss ratio) for all meshes. The implementation runs in O(n) and is # roughly based on the 'tipsify' algorithm (see <a href=" # http:www.cs.princeton.edugfxpubsSander_2007_%3ETRtipsy.pdf">this # paper<a>). # # If you intend to render huge models in hardware, this step might # be of interest to you. The <tt>#AI_CONFIG_PP_ICL_PTCACHE_SIZE<tt>config # setting can be used to fine-tune the cache optimization. # aiProcess_ImproveCacheLocality = 0x800 ## <hr>Searches for redundantunreferenced materials and removes them. # # This is especially useful in combination with the # #aiProcess_PretransformVertices and #aiProcess_OptimizeMeshes flags. # Both join small meshes with equal characteristics, but they can't do # their work if two meshes have different materials. Because several # material settings are lost during Assimp's import filters, # (and because many exporters don't check for redundant materials), huge # models often have materials which are are defined several times with # exactly the same settings. # # Several material settings not contributing to the final appearance of # a surface are ignored in all comparisons (e.g. the material name). # So, if you're passing additional information through the # content pipeline (probably using #magic# material names), don't # specify this flag. Alternatively take a look at the # <tt>#AI_CONFIG_PP_RRM_EXCLUDE_LIST<tt> setting. # aiProcess_RemoveRedundantMaterials = 0x1000 ## <hr>This step tries to determine which meshes have normal vectors # that are facing inwards and inverts them. # # The algorithm is simple but effective: # the bounding box of all vertices + their normals is compared against # the volume of the bounding box of all vertices without their normals. # This works well for most objects, problems might occur with planar # surfaces. However, the step tries to filter such cases. # The step inverts all in-facing normals. Generally it is recommended # to enable this step, although the result is not always correct. # aiProcess_FixInfacingNormals = 0x2000 ## <hr>This step splits meshes with more than one primitive type in # homogeneous sub-meshes. # # The step is executed after the triangulation step. After the step # returns, just one bit is set in aiMesh::mPrimitiveTypes. This is # especially useful for real-time rendering where point and line # primitives are often ignored or rendered separately. # You can use the <tt>#AI_CONFIG_PP_SBP_REMOVE<tt> option to specify which # primitive types you need. This can be used to easily exclude # lines and points, which are rarely used, from the import. # aiProcess_SortByPType = 0x8000 ## <hr>This step searches all meshes for degenerate primitives and # converts them to proper lines or points. # # A face is 'degenerate' if one or more of its points are identical. # To have the degenerate stuff not only detected and collapsed but # removed, try one of the following procedures: # <br><b>1.<b> (if you support lines and points for rendering but don't # want the degenerates)<br> # <ul> # <li>Specify the #aiProcess_FindDegenerates flag. # <li> # <li>Set the <tt>AI_CONFIG_PP_FD_REMOVE<tt> option to 1. This will # cause the step to remove degenerate triangles from the import # as soon as they're detected. They won't pass any further # pipeline steps. # <li> # <ul> # <br><b>2.<b>(if you don't support lines and points at all)<br> # <ul> # <li>Specify the #aiProcess_FindDegenerates flag. # <li> # <li>Specify the #aiProcess_SortByPType flag. This moves line and # point primitives to separate meshes. # <li> # <li>Set the <tt>AI_CONFIG_PP_SBP_REMOVE<tt> option to # @code aiPrimitiveType_POINTS | aiPrimitiveType_LINES # @endcode to cause SortByPType to reject point # and line meshes from the scene. # <li> # <ul> # @note Degenerate polygons are not necessarily evil and that's why # they're not removed by default. There are several file formats which # don't support lines or points, and some exporters bypass the # format specification and write them as degenerate triangles instead. # aiProcess_FindDegenerates = 0x10000 ## <hr>This step searches all meshes for invalid data, such as zeroed # normal vectors or invalid UV coords and removesfixes them. This is # intended to get rid of some common exporter errors. # # This is especially useful for normals. If they are invalid, and # the step recognizes this, they will be removed and can later # be recomputed, i.e. by the #aiProcess_GenSmoothNormals flag.<br> # The step will also remove meshes that are infinitely small and reduce # animation tracks consisting of hundreds if redundant keys to a single # key. The <tt>AI_CONFIG_PP_FID_ANIM_ACCURACY<tt> config property decides # the accuracy of the check for duplicate animation tracks. # aiProcess_FindInvalidData = 0x20000 ## <hr>This step converts non-UV mappings (such as spherical or # cylindrical mapping) to proper texture coordinate channels. # # Most applications will support UV mapping only, so you will # probably want to specify this step in every case. Note that Assimp is not # always able to match the original mapping implementation of the # 3D app which produced a model perfectly. It's always better to let the # modelling app compute the UV channels - 3ds max, Maya, Blender, # LightWave, and Modo do this for example. # # @note If this step is not requested, you'll need to process the # <tt>#AI_MATKEY_MAPPING<tt> material property in order to display all assets # properly. # aiProcess_GenUVCoords = 0x40000 ## <hr>This step applies per-texture UV transformations and bakes # them into stand-alone vtexture coordinate channels. # # UV transformations are specified per-texture - see the # <tt>#AI_MATKEY_UVTRANSFORM<tt> material key for more information. # This step processes all textures with # transformed input UV coordinates and generates a new (pre-transformed) UV channel # which replaces the old channel. Most applications won't support UV # transformations, so you will probably want to specify this step. # # @note UV transformations are usually implemented in real-time apps by # transforming texture coordinates at vertex shader stage with a 3x3 # (homogenous) transformation matrix. # aiProcess_TransformUVCoords = 0x80000 ## <hr>This step searches for duplicate meshes and replaces them # with references to the first mesh. # # This step takes a while, so don't use it if speed is a concern. # Its main purpose is to workaround the fact that many export # file formats don't support instanced meshes, so exporters need to # duplicate meshes. This step removes the duplicates again. Please # note that Assimp does not currently support per-node material # assignment to meshes, which means that identical meshes with # different materials are currently #not# joined, although this is # planned for future versions. # aiProcess_FindInstances = 0x100000 ## <hr>A postprocessing step to reduce the number of meshes. # # This will, in fact, reduce the number of draw calls. # # This is a very effective optimization and is recommended to be used # together with #aiProcess_OptimizeGraph, if possible. The flag is fully # compatible with both #aiProcess_SplitLargeMeshes and #aiProcess_SortByPType. # aiProcess_OptimizeMeshes = 0x200000 ## <hr>A postprocessing step to optimize the scene hierarchy. # # Nodes without animations, bones, lights or cameras assigned are # collapsed and joined. # # Node names can be lost during this step. If you use special 'tag nodes' # to pass additional information through your content pipeline, use the # <tt>#AI_CONFIG_PP_OG_EXCLUDE_LIST<tt> setting to specify a list of node # names you want to be kept. Nodes matching one of the names in this list won't # be touched or modified. # # Use this flag with caution. Most simple files will be collapsed to a # single node, so complex hierarchies are usually completely lost. This is not # useful for editor environments, but probably a very effective # optimization if you just want to get the model data, convert it to your # own format, and render it as fast as possible. # # This flag is designed to be used with #aiProcess_OptimizeMeshes for best # results. # # @note 'Crappy' scenes with thousands of extremely small meshes packed # in deeply nested nodes exist for almost all file formats. # #aiProcess_OptimizeMeshes in combination with #aiProcess_OptimizeGraph # usually fixes them all and makes them renderable. # aiProcess_OptimizeGraph = 0x400000 ## <hr>This step flips all UV coordinates along the y-axis and adjusts # material settings and bitangents accordingly. # # <b>Output UV coordinate system:<b> # @code # 0y|0y ---------- 1x|0y # | | # | | # | | # 0x|1y ---------- 1x|1y # @endcode # # You'll probably want to consider this flag if you use Direct3D for # rendering. The #aiProcess_ConvertToLeftHanded flag supersedes this # setting and bundles all conversions typically required for D3D-based # applications. # aiProcess_FlipUVs = 0x800000 ## <hr>This step adjusts the output face winding order to be CW. # # The default face winding order is counter clockwise (CCW). # # <b>Output face order:<b> # @code # x2 # # x0 # x1 # @endcode # aiProcess_FlipWindingOrder = 0x1000000 ## <hr>This step splits meshes with many bones into sub-meshes so that each # su-bmesh has fewer or as many bones as a given limit. # aiProcess_SplitByBoneCount = 0x2000000 ## <hr>This step removes bones losslessly or according to some threshold. # # In some cases (i.e. formats that require it) exporters are forced to # assign dummy bone weights to otherwise static meshes assigned to # animated meshes. Full, weight-based skinning is expensive while # animating nodes is extremely cheap, so this step is offered to clean up # the data in that regard. # # Use <tt>#AI_CONFIG_PP_DB_THRESHOLD<tt> to control this. # Use <tt>#AI_CONFIG_PP_DB_ALL_OR_NONE<tt> if you want bones removed if and # only if all bones within the scene qualify for removal. # aiProcess_Debone = 0x4000000 aiProcess_GenEntityMeshes = 0x100000 aiProcess_OptimizeAnimations = 0x200000 aiProcess_FixTexturePaths = 0x200000 ## @def aiProcess_ConvertToLeftHanded # @brief Shortcut flag for Direct3D-based applications. # # Supersedes the #aiProcess_MakeLeftHanded and #aiProcess_FlipUVs and # #aiProcess_FlipWindingOrder flags. # The output data matches Direct3D's conventions: left-handed geometry, upper-left # origin for UV coordinates and finally clockwise face order, suitable for CCW culling. # # @deprecated # aiProcess_ConvertToLeftHanded = ( \ aiProcess_MakeLeftHanded | \ aiProcess_FlipUVs | \ aiProcess_FlipWindingOrder | \ 0 ) ## @def aiProcessPreset_TargetRealtimeUse_Fast # @brief Default postprocess configuration optimizing the data for real-time rendering. # # Applications would want to use this preset to load models on end-user PCs, # maybe for direct use in game. # # If you're using DirectX, don't forget to combine this value with # the #aiProcess_ConvertToLeftHanded step. If you don't support UV transformations # in your application apply the #aiProcess_TransformUVCoords step, too. # @note Please take the time to read the docs for the steps enabled by this preset. # Some of them offer further configurable properties, while some of them might not be of # use for you so it might be better to not specify them. # aiProcessPreset_TargetRealtime_Fast = ( \ aiProcess_CalcTangentSpace | \ aiProcess_GenNormals | \ aiProcess_JoinIdenticalVertices | \ aiProcess_Triangulate | \ aiProcess_GenUVCoords | \ aiProcess_SortByPType | \ 0 ) ## @def aiProcessPreset_TargetRealtime_Quality # @brief Default postprocess configuration optimizing the data for real-time rendering. # # Unlike #aiProcessPreset_TargetRealtime_Fast, this configuration # performs some extra optimizations to improve rendering speed and # to minimize memory usage. It could be a good choice for a level editor # environment where import speed is not so important. # # If you're using DirectX, don't forget to combine this value with # the #aiProcess_ConvertToLeftHanded step. If you don't support UV transformations # in your application apply the #aiProcess_TransformUVCoords step, too. # @note Please take the time to read the docs for the steps enabled by this preset. # Some of them offer further configurable properties, while some of them might not be # of use for you so it might be better to not specify them. # aiProcessPreset_TargetRealtime_Quality = ( \ aiProcess_CalcTangentSpace | \ aiProcess_GenSmoothNormals | \ aiProcess_JoinIdenticalVertices | \ aiProcess_ImproveCacheLocality | \ aiProcess_LimitBoneWeights | \ aiProcess_RemoveRedundantMaterials | \ aiProcess_SplitLargeMeshes | \ aiProcess_Triangulate | \ aiProcess_GenUVCoords | \ aiProcess_SortByPType | \ aiProcess_FindDegenerates | \ aiProcess_FindInvalidData | \ 0 ) ## @def aiProcessPreset_TargetRealtime_MaxQuality # @brief Default postprocess configuration optimizing the data for real-time rendering. # # This preset enables almost every optimization step to achieve perfectly # optimized data. It's your choice for level editor environments where import speed # is not important. # # If you're using DirectX, don't forget to combine this value with # the #aiProcess_ConvertToLeftHanded step. If you don't support UV transformations # in your application, apply the #aiProcess_TransformUVCoords step, too. # @note Please take the time to read the docs for the steps enabled by this preset. # Some of them offer further configurable properties, while some of them might not be # of use for you so it might be better to not specify them. # aiProcessPreset_TargetRealtime_MaxQuality = ( \ aiProcessPreset_TargetRealtime_Quality | \ aiProcess_FindInstances | \ aiProcess_ValidateDataStructure | \ aiProcess_OptimizeMeshes | \ 0 )