Defines the material system of the library. More...

#include "types.h"

Classes
struct	aiUVTransform
	Defines how an UV channel is transformed. More...

struct	endif
	*/ More...

Macros
#define	AI_DEFAULT_MATERIAL_NAME "DefaultMaterial"

Enumerations
enum	aiTextureOp { aiTextureOp_Multiply = 0x0, aiTextureOp_Add = 0x1, aiTextureOp_Subtract = 0x2, aiTextureOp_Divide = 0x3, aiTextureOp_SmoothAdd = 0x4, aiTextureOp_SignedAdd = 0x5 }
	Defines how the Nth texture of a specific type is combined with the result of all previous layers. More...

enum	aiTextureMapMode { aiTextureMapMode_Wrap = 0x0, aiTextureMapMode_Clamp = 0x1, aiTextureMapMode_Decal = 0x3, aiTextureMapMode_Mirror = 0x2 }
	Defines how UV coordinates outside the [0...1] range are handled. More...

enum	aiTextureMapping { aiTextureMapping_UV = 0x0, aiTextureMapping_SPHERE = 0x1, aiTextureMapping_CYLINDER = 0x2, aiTextureMapping_BOX = 0x3, aiTextureMapping_PLANE = 0x4, aiTextureMapping_OTHER = 0x5 }
	Defines how the mapping coords for a texture are generated. More...

enum	aiTextureType { aiTextureType_NONE = 0x0, aiTextureType_DIFFUSE = 0x1, aiTextureType_SPECULAR = 0x2, aiTextureType_AMBIENT = 0x3, aiTextureType_EMISSIVE = 0x4, aiTextureType_HEIGHT = 0x5, aiTextureType_NORMALS = 0x6, aiTextureType_SHININESS = 0x7, aiTextureType_OPACITY = 0x8, aiTextureType_DISPLACEMENT = 0x9, aiTextureType_LIGHTMAP = 0xA, aiTextureType_REFLECTION = 0xB, aiTextureType_UNKNOWN = 0xC }
	Defines the purpose of a texture. More...

enum	aiShadingMode { aiShadingMode_Flat = 0x1, aiShadingMode_Gouraud = 0x2, aiShadingMode_Phong = 0x3, aiShadingMode_Blinn = 0x4, aiShadingMode_Toon = 0x5, aiShadingMode_OrenNayar = 0x6, aiShadingMode_Minnaert = 0x7, aiShadingMode_CookTorrance = 0x8, aiShadingMode_NoShading = 0x9, aiShadingMode_Fresnel = 0xa }
	Defines all shading models supported by the library. More...

enum	aiTextureFlags { aiTextureFlags_Invert = 0x1, aiTextureFlags_UseAlpha = 0x2, aiTextureFlags_IgnoreAlpha = 0x4 }
	Defines some mixed flags for a particular texture. More...

enum	aiBlendMode { aiBlendMode_Default = 0x0, aiBlendMode_Additive = 0x1 }
	Defines alpha-blend flags. More...

Variables
struct aiUVTransform	PACK_STRUCT

Detailed Description

Defines the material system of the library.

Enumeration Type Documentation

§ aiBlendMode

enum aiBlendMode

Defines alpha-blend flags.

If you're familiar with OpenGL or D3D, these flags aren't new to you. They define how the final color value of a pixel is computed, basing on the previous color at that pixel and the new color value from the material. The blend formula is:

SourceColor * SourceBlend + DestColor * DestBlend

where <DestColor> is the previous color in the framebuffer at this position and <SourceColor> is the material colro before the transparency calculation.
This corresponds to the #AI_MATKEY_BLEND_FUNC property.

Enumerator

aiBlendMode_Default

Formula:

SourceColor*SourceAlpha + DestColor*(1-SourceAlpha)

aiBlendMode_Additive

Additive blending.

Formula:

SourceColor*1 + DestColor*1

§ aiShadingMode

enum aiShadingMode

Defines all shading models supported by the library.

The list of shading modes has been taken from Blender. See Blender documentation for more information. The API does not distinguish between "specular" and "diffuse" shaders (thus the specular term for diffuse shading models like Oren-Nayar remains undefined).
Again, this value is just a hint. Assimp tries to select the shader whose most common implementation matches the original rendering results of the 3D modeller which wrote a particular model as closely as possible.

Enumerator
aiShadingMode_Flat	Flat shading. Shading is done on per-face base, diffuse only. Also known as 'faceted shading'.
aiShadingMode_Gouraud	Simple Gouraud shading.
aiShadingMode_Phong	Phong-Shading -.
aiShadingMode_Blinn	Phong-Blinn-Shading.
aiShadingMode_Toon	Toon-Shading per pixel. Also known as 'comic' shader.
aiShadingMode_OrenNayar	OrenNayar-Shading per pixel. Extension to standard Lambertian shading, taking the roughness of the material into account
aiShadingMode_Minnaert	Minnaert-Shading per pixel. Extension to standard Lambertian shading, taking the "darkness" of the material into account
aiShadingMode_CookTorrance	CookTorrance-Shading per pixel. Special shader for metallic surfaces.
aiShadingMode_NoShading	No shading at all. Constant light influence of 1.0.
aiShadingMode_Fresnel	Fresnel shading.

§ aiTextureFlags

enum aiTextureFlags

Defines some mixed flags for a particular texture.

Usually you'll instruct your cg artists how textures have to look like ... and how they will be processed in your application. However, if you use Assimp for completely generic loading purposes you might also need to process these flags in order to display as many 'unknown' 3D models as possible correctly.

This corresponds to the #AI_MATKEY_TEXFLAGS property.

Enumerator

aiTextureFlags_Invert

The texture's color values have to be inverted (componentwise 1-n)

aiTextureFlags_UseAlpha

Explicit request to the application to process the alpha channel of the texture.

Mutually exclusive with aiTextureFlags_IgnoreAlpha. These flags are set if the library can say for sure that the alpha channel is used/is not used. If the model format does not define this, it is left to the application to decide whether the texture alpha channel - if any - is evaluated or not.

aiTextureFlags_IgnoreAlpha

Explicit request to the application to ignore the alpha channel of the texture.

Mutually exclusive with aiTextureFlags_UseAlpha.

§ aiTextureMapMode

enum aiTextureMapMode

Defines how UV coordinates outside the [0...1] range are handled.

Commonly refered to as 'wrapping mode'.

Enumerator
aiTextureMapMode_Wrap	A texture coordinate u\|v is translated to u%1\|v%1.
aiTextureMapMode_Clamp	Texture coordinates outside [0...1] are clamped to the nearest valid value.
aiTextureMapMode_Decal	If the texture coordinates for a pixel are outside [0...1] the texture is not applied to that pixel.
aiTextureMapMode_Mirror	A texture coordinate u\|v becomes u%1\|v%1 if (u-(u%1))%2 is zero and 1-(u%1)\|1-(v%1) otherwise.

§ aiTextureMapping

enum aiTextureMapping

Defines how the mapping coords for a texture are generated.

Real-time applications typically require full UV coordinates, so the use of the aiProcess_GenUVCoords step is highly recommended. It generates proper UV channels for non-UV mapped objects, as long as an accurate description how the mapping should look like (e.g spherical) is given. See the #AI_MATKEY_MAPPING property for more details.

Enumerator
aiTextureMapping_UV	The mapping coordinates are taken from an UV channel. The #AI_MATKEY_UVWSRC key specifies from which UV channel the texture coordinates are to be taken from (remember, meshes can have more than one UV channel).
aiTextureMapping_SPHERE	Spherical mapping.
aiTextureMapping_CYLINDER	Cylindrical mapping.
aiTextureMapping_BOX	Cubic mapping.
aiTextureMapping_PLANE	Planar mapping.
aiTextureMapping_OTHER	Undefined mapping. Have fun.

§ aiTextureOp

enum aiTextureOp

Defines how the Nth texture of a specific type is combined with the result of all previous layers.

Example (left: key, right: value):

DiffColor0     - gray
DiffTextureOp0 - aiTextureOpMultiply
DiffTexture0   - tex1.png
DiffTextureOp0 - aiTextureOpAdd
DiffTexture1   - tex2.png

Written as equation, the final diffuse term for a specific pixel would be:

diffFinal = DiffColor0 * sampleTex(DiffTexture0,UV0) +

sampleTex(DiffTexture1,UV0) * diffContrib;

where 'diffContrib' is the intensity of the incoming light for that pixel.

Enumerator
aiTextureOp_Multiply	T = T1 * T2.
aiTextureOp_Add	T = T1 + T2.
aiTextureOp_Subtract	T = T1 - T2.
aiTextureOp_Divide	T = T1 / T2.
aiTextureOp_SmoothAdd	T = (T1 + T2) - (T1 * T2)
aiTextureOp_SignedAdd	T = T1 + (T2-0.5)

§ aiTextureType

enum aiTextureType

Defines the purpose of a texture.

This is a very difficult topic. Different 3D packages support different kinds of textures. For very common texture types, such as bumpmaps, the rendering results depend on implementation details in the rendering pipelines of these applications. Assimp loads all texture references from the model file and tries to determine which of the predefined texture types below is the best choice to match the original use of the texture as closely as possible.

In content pipelines you'll usually define how textures have to be handled, and the artists working on models have to conform to this specification, regardless which 3D tool they're using.

Enumerator
aiTextureType_NONE	Dummy value. No texture, but the value to be used as 'texture semantic' (#aiMaterialProperty::mSemantic) for all material properties not related to textures.
aiTextureType_DIFFUSE	The texture is combined with the result of the diffuse lighting equation.
aiTextureType_SPECULAR	The texture is combined with the result of the specular lighting equation.
aiTextureType_AMBIENT	The texture is combined with the result of the ambient lighting equation.
aiTextureType_EMISSIVE	The texture is added to the result of the lighting calculation. It isn't influenced by incoming light.
aiTextureType_HEIGHT	The texture is a height map. By convention, higher gray-scale values stand for higher elevations from the base height.
aiTextureType_NORMALS	The texture is a (tangent space) normal-map. Again, there are several conventions for tangent-space normal maps. Assimp does (intentionally) not distinguish here.
aiTextureType_SHININESS	The texture defines the glossiness of the material. The glossiness is in fact the exponent of the specular (phong) lighting equation. Usually there is a conversion function defined to map the linear color values in the texture to a suitable exponent. Have fun.
aiTextureType_OPACITY	The texture defines per-pixel opacity. Usually 'white' means opaque and 'black' means 'transparency'. Or quite the opposite. Have fun.
aiTextureType_DISPLACEMENT	Displacement texture. The exact purpose and format is application-dependent. Higher color values stand for higher vertex displacements.
aiTextureType_LIGHTMAP	Lightmap texture (aka Ambient Occlusion) Both 'Lightmaps' and dedicated 'ambient occlusion maps' are covered by this material property. The texture contains a scaling value for the final color value of a pixel. Its intensity is not affected by incoming light.
aiTextureType_REFLECTION	Reflection texture. Contains the color of a perfect mirror reflection. Rarely used, almost never for real-time applications.
aiTextureType_UNKNOWN	Unknown texture. A texture reference that does not match any of the definitions above is considered to be 'unknown'. It is still imported, but is excluded from any further postprocessing.

Classes

Macros

Enumerations

Variables