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/**
* Definitions for import post processing steps.
*/
module assimp.postprocess;
extern ( C ) {
/**
* Defines the flags for all possible post processing steps.
*
* See: aiImportFile, aiImportFileEx
*/
enum aiPostProcessSteps {
/**
* 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 is a
* config setting, AI_CONFIG_PP_CT_MAX_SMOOTHING_ANGLE,
* which allows you to specify a maximum smoothing angle for the
* algorithm. However, usually you will want to use the default value.
*/
CalcTangentSpace = 0x1,
/**
* Identifies and joins identical vertex data sets within all imported
* meshes.
*
* After this step is run each mesh does contain only unique vertices
* anymore, so a vertex is possibly 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 will just waste
* rendering time. If this flag is not specified, no vertices
* are referenced by more than one face and no index buffer is
* required for rendering.
*/
JoinIdenticalVertices = 0x2,
/**
* Converts all the imported data to a left-handed coordinate space.
*
* By default the data is returned in a right-handed coordinate space
* which for example OpenGL prefers. In this space, +X points to the
* right, +Z points towards the viewer and 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 will probably want to consider this flag if you use Direct3D for
* rendering. The ConvertToLeftHanded flag supersedes this
* setting and bundles all conversions typically required for D3D-based
* applications.
*/
MakeLeftHanded = 0x4,
/**
* 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 all higher faces to triangles.
* Line and point primitives are not modified!.
*
* If you want »triangles only« with no other kinds of primitives,
* specify both Triangulate and SortByPType and
* ignore all point and line meshes when you process Assimp's output.
*/
Triangulate = 0x8,
/**
* 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, AI_CONFIG_PP_RVC_FLAGS. This is quite useful if
* you don't need all parts of the output structure. Especially vertex
* colors are rarely used today.
*
* Calling this step to remove unrequired stuff from the pipeline as
* early as possible results in an increased performance and a better
* optimized output data structure.
*
* This step is also useful if you want to force Assimp to recompute
* normals or tangents since the corresponding steps don't recompute them
* if they have already been loaded from the source asset.
*
* 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, it has per-face vertex colors. Because of the vertex
* colors (which are not even used by most apps),
* JoinIdenticalVertices cannot join vertices at the same
* position. By using this step, unneeded components are excluded as
* early as possible thus opening more room for internal optimzations.
*/
RemoveComponent = 0x10,
/**
* Generates normals for all faces of all meshes.
*
* This is ignored if normals are already there at the time where this
* flag is evaluated. Model importers try to load them from the source
* file, so they are usually already there. Face normals are shared
* between all points of a single face, so a single point can have
* multiple normals, which, in other words, enforces the library to
* duplicate vertices in some cases. JoinIdenticalVertices
* is useless then.
*
* This flag may not be specified together with
* GenSmoothNormals.
*/
GenNormals = 0x20,
/**
* Generates smooth normals for all vertices in the mesh.
*
* This is ignored if normals are already there at the time where this
* flag is evaluated. Model importers try to load them from the source file, so
* they are usually already there.
*
* There is a configuration option,
* AI_CONFIG_PP_GSN_MAX_SMOOTHING_ANGLE 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°) results in
* very good visual appearance.
*/
GenSmoothNormals = 0x40,
/**
* Splits large meshes into smaller submeshes.
*
* This is quite useful for realtime rendering where the number of triangles
* which can be maximally processed in a single draw-call is usually limited
* by the video driver/hardware. 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
* AI_CONFIG_PP_SLM_VERTEX_LIMIT and
* AI_CONFIG_PP_SLM_TRIANGLE_LIMIT settings. The default
* values are AI_SLM_DEFAULT_MAX_VERTICES and
* AI_SLM_DEFAULT_MAX_TRIANGLES.
*
* Note that splitting is generally a time-consuming task, but not if
* there's nothing to split. The use of this step is recommended for most
* users.
*/
SplitLargeMeshes = 0x80,
/**
* Removes the node graph and pre-transforms all vertices with the local
* transformation matrices of their nodes.
*
* The output scene does still contain nodes, however, there is only a
* root node with children, each one referencing only one mesh, 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 that have no 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 AI_CONFIG_PP_PTV_NORMALIZE configuration
* property can be set to normalize the scene's spatial dimension
* to the -1...1 range.
*/
PreTransformVertices = 0x100,
/**
* Limits the number of bones simultaneously affecting a single vertex to
* a maximum value.
*
* If any vertex is affected by more than that 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 (AI_LMW_MAX_WEIGHTS),
* but you can use the #AI_CONFIG_PP_LBW_MAX_WEIGHTS 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 for you.
*/
LimitBoneWeights = 0x200,
/**
* 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 to capture Assimp's log output if you use this flag,
* so you can easily find ot what's actually wrong if a file fails the
* validation. The validator is quite rude and will find all
* inconsistencies in the data structure.
*
* Plugin developers are recommended to use it to debug their loaders.
*
* There are two types of validation failures:
*
* - 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, see
aiGetErrorString() for the
* error message.
* - 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,
AI_SCENE_FLAGS_VALIDATION_WARNING is
* set in aiScene::mFlags
*
*
* This post-processing step is not time-consuming. It's use is not
* compulsory, but recommended.
*/
ValidateDataStructure = 0x400,
/**
* 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
* http://www.cs.princeton.edu/gfx/pubs/Sander_2007_%3ETR/tipsy.pdf).
*
* If you intend to render huge models in hardware, this step might
* be of interest for you. The AI_CONFIG_PP_ICL_PTCACHE_SIZE
* config setting can be used to fine-tune the cache optimization.
*/
ImproveCacheLocality = 0x800,
/**
* Searches for redundant/unreferenced materials and removes them.
*
* This is especially useful in combination with the
* PretransformVertices and 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 always 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; the material name is one of
* them. So, if you are passing additional information through the
* content pipeline (probably using »magic« material names), don't
* specify this flag. Alternatively take a look at the
* AI_CONFIG_PP_RRM_EXCLUDE_LIST setting.
*/
RemoveRedundantMaterials = 0x1000,
/**
* This step tries to determine which meshes have normal vectors that are
* acing inwards.
*
* The algorithm is simple but effective: The bounding box of all
* vertices and 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.
*/
FixInfacingNormals = 0x2000,
/**
* This step splits meshes with more than one primitive type in
* homogeneous submeshes.
*
* 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 AI_CONFIG_PP_SBP_REMOVE 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.
*/
SortByPType = 0x8000,
/**
* This step searches all meshes for degenerated primitives and converts
* them to proper lines or points.
*
* A face is »degenerated« if one or more of its points are identical.
* To have the degenerated stuff not only detected and collapsed but also
* removed, try one of the following procedures:
*
* 1. (if you support lines and points for rendering but don't
* want the degenerates)
*
* - Specify the
FindDegenerates flag.
* - Set the
AI_CONFIG_PP_FD_REMOVE option to 1. This will
* cause the step to remove degenerated triangles from the import
* as soon as they're detected. They won't pass any further
* pipeline steps.
*
*
* 2.(if you don't support lines and points at all ...)
*
* - Specify the
FindDegenerates flag.
* - Specify the
SortByPType flag. This moves line and
* point primitives to separate meshes.
* - Set the
AI_CONFIG_PP_SBP_REMOVE option to
* aiPrimitiveType_POINTS | aiPrimitiveType_LINES
* to cause SortByPType to reject point and line meshes from the
* scene.
*
*
* Note: Degenerated polygons are not necessarily bad and that's why
* they're not removed by default. There are several file formats
* which don't support lines or points. Some exporters bypass the
* format specification and write them as degenerated triangle
* instead.
*/
FindDegenerates = 0x10000,
/**
* This step searches all meshes for invalid data, such as zeroed normal
* vectors or invalid UV coords and removes/fixes 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, e.g. by the GenSmoothNormals step.
*
* 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 AI_CONFIG_PP_FID_ANIM_ACCURACY config property
* decides the accuracy of the check for duplicate animation tracks.
*/
FindInvalidData = 0x20000,
/**
* 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 tha 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 father app
* compute the UV channels, at least 3ds max, maja, blender, lightwave,
* modo, ... are able to achieve this.
*
* Note: If this step is not requested, you'll need to process the
* AI_MATKEY_MAPPING material property in order to
* display all assets properly.
*/
GenUVCoords = 0x40000,
/**
* This step applies per-texture UV transformations and bakes them to
* stand-alone vtexture coordinate channelss.
*
* UV transformations are specified per-texture – see the
* AI_MATKEY_UVTRANSFORM material key for more information.
* This step processes all textures with transformed input UV coordinates
* and generates new (pretransformed) UV channel which replace 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 realtime apps by
* transforming texture coordinates at vertex shader stage with a 3x3
* (homogenous) transformation matrix.
*/
TransformUVCoords = 0x80000,
/**
* This step searches for duplicate meshes and replaces duplicates with
* references to the first mesh.
*
* This step takes a while, don't use it if you have no time. Its main
* purpose is to workaround the limitation 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
* currently not support per-node material assignment to meshes, which
* means that identical meshes with differnent materials are currently
* not joined, although this is planned for future versions.
*/
FindInstances = 0x100000,
/**
* A postprocessing step to reduce the number of meshes.
*
* In fact, it will reduce the number of drawcalls.
*
* This is a very effective optimization and is recommended to be used
* together with OptimizeGraph, if possible. The flag is
* fully compatible with both SplitLargeMeshes and
* SortByPType.
*/
OptimizeMeshes = 0x200000,
/**
* A postprocessing step to optimize the scene hierarchy.
*
* Nodes with no 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
* AI_CONFIG_PP_OG_EXCLUDE_LIST 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, complex hierarchies are usually completely lost. That's
* note the right choice 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 OptimizeMeshes for
* best results.
*
* Note: »Crappy« scenes with thousands of extremely small meshes packed
* in deeply nested nodes exist for almost all file formats.
* OptimizeMeshes in combination with
* OptimizeGraph usually fixes them all and makes them
* renderable.
*/
OptimizeGraph = 0x400000,
/** This step flips all UV coordinates along the y-axis and adjusts
* material settings and bitangents accordingly.
*
* Output UV coordinate system:
* 0y|0y ---------- 1x|0y
* | |
* | |
* | |
* 0x|1y ---------- 1x|1y
* You'll probably want to consider this flag if you use Direct3D for
* rendering. The AI_PROCESS_CONVERT_TO_LEFT_HANDED flag
* supersedes this setting and bundles all conversions typically required
* for D3D-based applications.
*/
FlipUVs = 0x800000,
/**
* This step adjusts the output face winding order to be clockwise.
*
* The default face winding order is counter clockwise.
*
* Output face order:
* x2
*
* x0
* x1
*/
FlipWindingOrder = 0x1000000
}
/**
* Abbrevation for convenience.
*/
alias aiPostProcessSteps aiProcess;
/**
* Shortcut flag for Direct3D-based applications.
*
* Combines the MakeLeftHanded, FlipUVs and
* FlipWindingOrder flags. The output data matches Direct3D's
* conventions: left-handed geometry, upper-left origin for UV coordinates
* and clockwise face order, suitable for CCW culling.
*/
const aiPostProcessSteps AI_PROCESS_CONVERT_TO_LEFT_HANDED =
aiProcess.MakeLeftHanded |
aiProcess.FlipUVs |
aiProcess.FlipWindingOrder;
/**
* 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 ConvertToLeftHanded step. If you don't support UV
* transformations in your application, apply the
* TransformUVCoords step, too.
*
* Note: Please take the time to read the doc for the steps enabled by this
* preset. Some of them offer further configurable properties, some of
* them might not be of use for you so it might be better to not specify
* them.
*/
const aiPostProcessSteps AI_PROCESS_PRESET_TARGET_REALTIME_FAST =
aiProcess.CalcTangentSpace |
aiProcess.GenNormals |
aiProcess.JoinIdenticalVertices |
aiProcess.Triangulate |
aiProcess.GenUVCoords |
aiProcess.SortByPType;
/**
* Default postprocess configuration optimizing the data for real-time
* rendering.
*
* Unlike AI_PROCESS_PRESET_TARGET_REALTIME_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 ConvertToLeftHanded step. If you don't support UV
* transformations in your application, apply the
* TransformUVCoords step, too.
*
* Note: Please take the time to read the doc for the steps enabled by this
* preset. Some of them offer further configurable properties, some of
* them might not be of use for you so it might be better to not specify
* them.
*/
const aiPostProcessSteps AI_PROCESS_PRESET_TARGET_REALTIME_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;
/**
* 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 ConvertToLeftHanded step. If you don't support UV
* transformations in your application, apply the
* TransformUVCoords step, too.
*
* Note: Please take the time to read the doc for the steps enabled by this
* preset. Some of them offer further configurable properties, some of
* them might not be of use for you so it might be better to not specify
* them.
*/
const aiPostProcessSteps AI_PROCESS_PRESET_TARGET_REALTIME_MAX_QUALITY =
AI_PROCESS_PRESET_TARGET_REALTIME_QUALITY |
aiProcess.FindInstances |
aiProcess.ValidateDataStructure |
aiProcess.OptimizeMeshes;
}