Custom Settings for material cannot be set by .mtl file

Rhino Developer
1

I am importing a mesh for analysis with some C++ code. It parses the .mtl file to set values for the Custom Settings of several materials. I am able to find a home for all the parameters in the .mtl file:

# Rhino
newmtl material_2
Ka 0.0000 0.0000 0.0000
Kd 1.0000 0.0000 0.0000
Ks 1.0000 1.0000 1.0000
Tf 0.0000 0.0000 0.0000
d 1.0000
Ns 127.5000
newmtl Default
Ka 0.0000 0.0000 0.0000
Kd 0.9804 0.9804 0.9804
Ks 1.0000 1.0000 1.0000
Tf 0.0000 0.0000 0.0000
d 1.0000
Ns 0.0000
newmtl material_1
Ka 0.0000 0.0000 0.0000
Kd 0.5451 0.3529 0.0000
Ks 1.0000 1.0000 1.0000
Tf 0.0000 0.0000 0.0000
d 1.0000
Ns 38.2500
newmtl material_3
Ka 0.0000 0.0000 0.0000
Kd 1.0000 0.4980 0.0000
Ks 1.0000 1.0000 1.0000
Tf 0.0000 0.0000 0.0000
d 1.0000
Ns 0.0000

Ka is mapped to the ambient color (not shown in Custom Settings).
Kd is mapped to Color in Custom Settings.
Ks is mapped to Specular color (not shown in Custom Settings).
Tf is mapped to Emission color in Advanced Settings.
d is mapped to Transparency in Custom Settings.
Ns is maped to Gloss finish in Custom Settings.
I manually added a setting for Reflection polish in Advanced Settings.
I also manually added a setting for Reflectivity in Custom Settings.

These result in the Proerties: Material form looking like this for material_2:

image
image834×1002 76.8 KB

Two things surprise me after doing this:
(1) The .mtl file does not allow specifying Reflectivity in Custom Settings. I did this manually.
(2) Both the mtl file and Rhino C++ API do not allow specifying the Transparency clarity in Advanced Settings.

If I look at all the possible material properties:

image
image1289×796 281 KB

I do not see anything I can relate to Transparency clarity.

Here is the C++ code used to add material properties to the mesh:

// Create new material.
ON_Material mat;
// Read and process lines in mtl file for this material.
while (!done) {
	// Read next line in mtl file. Stop if EOF found.
	getline(mtl_file, line); if (line.empty() or mtl_file.eof()) { done = true; break; }
	// Use istringstream to parse line into words. Initialize color to black at start.
	istringstream iss(line); r = 0.0; g = 0.0; b = 0.0;
	// Get first word in line.
	if (iss >> s) {
		// Parse line according to first word.
		// This sets the ambient color.
		if (s == "Ka") { iss>>r>>g>>b; mat.SetAmbient(ON_Color(r*m, g*m, b*m)); }
		// This sets the Color in Custom Settings.
		else if (s == "Kd") { iss>> r>>g>>b; mat.SetDiffuse(ON_Color(r*m, g*m, b*m)); }
		// This sets the Specular color.
		else if (s == "Ks") { iss>>r>>g>>b; mat.SetSpecular(ON_Color(r*m, g*m, b*m)); }
		// This sets the Emission color in Advanced Settings.
		else if (s == "Tf") { iss>>r>>g>>b; mat.SetEmission(ON_Color(r*m, g*m, b*m)); }
		// This sets the Transparency in Custom Settings.
		else if (s == "d") { iss >> num; mat.SetTransparency(1.0 - num); }
		// This sets the shine in Custom Settings. Ns range is 0-255 = MaxShine.
		else if (s == "Ns") { iss >> num; mat.m_shine = num; }
		// A new material definition has been found so this one is now done.
		else if (s == "newmtl") { done = true; }
	}
}
// Finish processing of .mtl file for this material.
if (done and !jpg) {
	// Convert material name to wchar_t* format.
	CA2W material_namew(material_name.c_str(), CP_UTF8);
	// Set name of material.
	mat.SetName(material_namew);
	// This sets the Reflectivity in Custom Settings.
	mat.SetReflectivity(0.05);
	// This sets the Reflection Polish in Advanced Settings to 0%.
	mat.m_reflection_glossiness = 1.0;
	// Turn on self-illumination for brighter view.
	mat.SetDisableLighting(false);
	// Get material index for new material.
	const int32_t matIndex = pDoc->m_material_table.AddMaterial(mat);
	// Add Material index to mesh attributes.
	attribs.m_material_index = matIndex;
	// Set color source to be from material.
	attribs.SetColorSource(ON::color_from_material);
	// If mesh has colors, specify layer as source of material.
	if (has_colors) { attribs.SetMaterialSource(ON::material_from_layer); }
	// Otherwise secify object as source of material.
	else { attribs.SetMaterialSource(ON::material_from_object); }
}

Regards,
Terry.