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*/
/** @file aiPostProcess.h
* @brief Definitions for import post processing steps
*/
#ifndef AI_POSTPROCESS_H_INC
#define AI_POSTPROCESS_H_INC
#include "aiTypes.h"
#ifdef __cplusplus
extern "C" {
#endif
// -----------------------------------------------------------------------------------
/** @enum aiPostProcessSteps
* @brief Defines the flags for all possible post processing steps.
*
* @see Importer::ReadFile
* @see aiImportFile
* @see 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's 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'll
* want to leave it at the default value. Thanks.
*/
aiProcess_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'll 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.
*/
aiProcess_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'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,
// -------------------------------------------------------------------------
/**
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, try the following
* solution:
*
* - Specify both #aiProcess_Triangulate and #aiProcess_SortByPType
* Ignore all point and line meshes when you process assimp's output
*
*/
aiProcess_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. 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, it has per-face vertex colors. Vertex positions can't be
* shared, thus the #aiProcess_JoinIdenticalVertices step fails to
* optimize the data. Just because 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 optimzations.
*/
aiProcess_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're 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.
* #aiProcess_JoinIdenticalVertices is *senseless* then.
*
* This flag may not be specified together with #aiProcess_GenSmoothNormals.
*/
aiProcess_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're usually already there.
*
* This flag may (of course) not be specified together with
* #aiProcess_GenNormals. There's 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 a 'hard' seam between two faces.
* Using a decent angle here (e.g. 80°) results in very good visual
* appearance.
*/
aiProcess_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.
*/
aiProcess_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 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 #AI_CONFIG_PP_PTV_NORMALIZE configuration property
* can be set to normalize the scene's spatial dimension to the -1...1
* range.
*/
aiProcess_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 (defined as #AI_LMW_MAX_WEIGHTS in
* aiConfig.h), 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.
*/
aiProcess_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. #Importer::GetErrorString() or #aiGetErrorString()
* carry the error message around.
* - 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.
*/
aiProcess_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 this
* paper).
*
* If you intend to render huge models in hardware, this step might
* be of interest for you. The #AI_CONFIG_PP_ICL_PTCACHE_SIZEconfig
* setting can be used to fine-tune the cache optimization.
*/
aiProcess_ImproveCacheLocality = 0x800,
// -------------------------------------------------------------------------
/**
Searches for redundant/unreferenced 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 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're 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.
*/
aiProcess_RemoveRedundantMaterials = 0x1000,
// -------------------------------------------------------------------------
/**
This step tries to determine which meshes have normal vectors
* that are facing inwards. 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,
// -------------------------------------------------------------------------
/**
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.
*/
aiProcess_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&points for rendering but don't
* want the degenerates)
*
* - Specify the #aiProcess_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&points at all ...)
*
* - Specify the #aiProcess_FindDegenerates flag.
*
* - Specify the #aiProcess_SortByPType flag. This moves line and
* point primitives to separate meshes.
*
* - Set the AI_CONFIG_PP_SBP_REMOVE option to
* @code aiPrimitiveType_POINTS | aiPrimitiveType_LINES
* @endcode to cause SortByPType to reject point
* and line meshes from the scene.
*
*
* @note Degenerated 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 ... some exporters bypass the
* format specification and write them as degenerated triangle instead.
*/
aiProcess_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, i.e. by the #aiProcess_GenSmoothNormals flag.
* 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.
*/
aiProcess_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.
*/
aiProcess_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.
*/
aiProcess_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.
*/
aiProcess_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 #aiProcess_OptimizeGraph, if possible. The flag is fully
* compatible with both #aiProcess_SplitLargeMeshes and #aiProcess_SortByPType.
*/
aiProcess_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 not
* 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 #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,
// -------------------------------------------------------------------------
/**
This step flips all UV coordinates along the y-axis and adjusts
* material settings and bitangents accordingly.
*
Output UV coordinate system:
* @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,
// -------------------------------------------------------------------------
/**
This step adjusts the output face winding order to be cw.
*
* The default face winding order is counter clockwise.
*
Output face order:
* @code
* x2
*
* x0
* x1
* @endcode
*/
aiProcess_FlipWindingOrder = 0x1000000,
// -------------------------------------------------------------------------
/**
This step splits meshes with many bones into submeshes so that each
* submesh has fewer or as many bones as a given limit.
*/
aiProcess_SplitByBoneCount = 0x2000000,
// -------------------------------------------------------------------------
/**
This step removes bones losslessly or according to some threshold.
* In some cases (i.e. format that require it) exporters are forced to
* assign dummy bone weights to otherwise static meshes assigned to
* animated meshes. Since full, weight-based skinning is expensive but
* animating nodes is extremely cheap, this step is offered to cleanup
* the data in that regard.
*
* Use #AI_CONFIG_PP_DB_THRESHOLD to control this.
* Use #AI_CONFIG_PP_DB_ALL_OR_NONE 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
*/
#define 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 doc to 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.
*/
#define 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 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.
*/
#define 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 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.
*/
#define aiProcessPreset_TargetRealtime_MaxQuality ( \
aiProcessPreset_TargetRealtime_Quality | \
aiProcess_FindInstances | \
aiProcess_ValidateDataStructure | \
aiProcess_OptimizeMeshes | \
aiProcess_Debone | \
0 )
#ifdef __cplusplus
} // end of extern "C"
#endif
#endif // AI_POSTPROCESS_H_INC