Material instruction reference


ig3d_GetMeshMaterialInfo_i_s, ig3d_SetMeshMaterialInfo_is, ig3d_SetMeshMaterialInfo_is, ig3d_GetObjectMaterialInfo_si_s and ig3d_SetObjectMaterialInfo_sis
are use the multi-line string [materialInfo] parameter (or return value). We are covering the format of this string here.
This string has multiple lines, the first line is the name of the material and the second line contains the number of material instructions that will follow.
The other lines are these instructions. They make up the appearance of the material.
The instructions are organized in a line-delimited list with one line for each instruction.
An instruction has the following syntax: [setting]=[value_1, ..., value_n]
The types and amounts of values for a setting vary from setting to setting.
NOTE: The material instructions are the same as in the WTF file format!
Here is a sample instruction:
lux=true
This makes the material immune to lighting (takes only one boolean value).

Since iGame3D is built on top of OpenGL, most settings you see here do exactly the same as the corresponding OpenGL state function calls.
Because the OpenGL functions are well-documented, we are just telling what functions to look for in each setting.
Here is a list of all supported settings and their value types:
lux=Boolean
smooth=Integer
color=Real, Real, Real, Real
ambient=Real, Real, Real, Real
diffuse=Real, Real, Real, Real
specular=Real, Real, Real, Real
shininess=Real
emission=Real, Real, Real, Real
blend=Integer
texture=Integer,local file string
wire=Real
depth=Integer
shader=local file string
"lux":
If the value of "lux" is true, then this material will ignore any lighting and will appear at full brightness (use for skyboxes for example).

"smooth":
If the value of "smooth" is 1, then the material will be smooth-shaded (goraud-shaded). If the material is a mesh material you should first select the mesh
that is using this material and call ig3d_MakeMeshSmoothShaded_b to calculate the vertex normals used in this type of shading.
If the value is 0, then the material will be flat-shaded.
The value is of type integer because in the future more shading types might be added.
"color":
Sets the color of the material using four values (red, green, blue and alpha components).

"ambient", "diffuse", "specular", "shininess", "emission":
See a OpenGL reference for the uses of GL_AMBIENT, GL_DIFFUSE, GL_SPECULAR, GL_SHININESS, GL_EMISSION with the function glMaterialfv.
Here's an example: ambient=0.1,0.1,0.1,1.0 would be glMaterialfv(GL_FRONT, GL_AMBIENT, {0.1,0.1,0.1,1.0});

"blend":
If the value of "blend" is 1, then blending will be turned on, which means that the opacity of the material will be determined by the alpha channel
of its texture and the alpha value of the "diffuse" setting, 0 meaning complete invisible and 1 meaning opaque.
By default, blending is off (blend=0).

"texture":
The first value is the texture unit and the second value the local path of the texture file to be used. This should be a .png somewhere in iGame3D directory or its subdirectories.
The texture unit ranges from 1 to 8, more are not supported by iGame3D. Some graphics cards support less, some support more. Apply textures to multiple units to do multitexturing.
If no texture is assigned to any of the units, the material will have the color specified in the "color" setting.
Example usage: texture=1,data/images/wood.png
"wire":
If the value of "wire" is not 0, then the material will be wireframe and the value sets the line width in pixels.
"depth":
By default the value of "depth" is 1, which means that depth-testing (sometimes called z-testing) is performed when drawing the geometry of this material.
With a value of 0 you can turn this off. You might use this for some blending materials or where depth testing does not matter.
"shader":
Takes a local path to a folder containing vertex and fragment shader files. Only the Mac version of iGame3D supports vertex and fragment shaders as of now. The specified folder should contain
these three files: VertexProgram, FragmentProgram and FragmentProgram_ATI. VertexProgram is written in ARBvp1.0 and FragmentProgram in ARBfp1.0. The FragmentProgram_ATI (language ATIfs1.0) is used
on cards that don't support FragmentProgram and that concerns a lot of cards used in Macs.
This is allows you to apply a custom shader to a material!
Example usage: shader=data/Shaders/bump/