Summary: Discusses how to modify the intensity of a material's texture.

I would like to change the intensity, or blend, percentage of a basic material's texture. How can I do this using the .NET SDK?

See the following example

public override IRhinoCommand.result RunCommand(IRhinoCommandContext context)
{
  // Pick a renderable object
  MRhinoGetObject go = new MRhinoGetObject();
  go.SetCommandPrompt("Select surface, polysurface, or mesh");
  go.SetGeometryFilter(IRhinoGetObject.GEOMETRY_TYPE_FILTER.surface_object | 
                       IRhinoGetObject.GEOMETRY_TYPE_FILTER.polysrf_object | 
                       IRhinoGetObject.GEOMETRY_TYPE_FILTER.mesh_object);
  go.GetObjects(1, 1);
  if (go.CommandResult() != IRhinoCommand.result.success)
    return go.CommandResult();
 
  // Validate the object
  IRhinoObject obj = go.Object(0).Object();
  if (obj == null)
    return IRhinoCommand.result.failure;
 
  // Get the object's material index
  int mat_index = obj.Attributes().m_material_index;
  if (mat_index >= 0)
  {
    // Get the object's material
    IRhinoMaterial mat = context.m_doc.m_material_table[mat_index];
    if (mat != null)
    {
      // See if the material has a texture. In this example, we will look
      // for a bitmap texture
      int tex_index = mat.FindTexture(null, IOnTexture.TYPE.bitmap_texture);
      if (tex_index >= 0)
      {
        // Make a copy of the object's material
        OnMaterial new_mat = new OnMaterial(mat);
 
        // Get the bitmap texture
        OnTexture tex = new_mat.m_textures[tex_index];
 
        // The blend constant ranges from 0.0 to 1.0 (inclusive).
        double blend_constant = tex.m_blend_constant_A;
 
        // Convert to a percentage (can probably skip this step)
        int blend_percent = OnUtil.ON_Round(blend_constant * 100.0);
 
        // Modify the percentage (1/2 will do for this example)
        int new_blend_percent = OnUtil.ON_Round(blend_percent / 2);
 
        // Convert back to a value between 0.0 to 1.0
        double new_blend_constant = (double)(new_blend_percent / 100.0);
 
        // Update the texture
        tex.m_blend_constant_A = new_blend_constant;
 
        // Modify the mode if necessary
        if (tex.m_blend_constant_A < 1.0)
          tex.m_mode = IOnTexture.MODE.blend_texture;
        else
          tex.m_mode = IOnTexture.MODE.decal_texture;
 
        // Modify the object's material
        if( context.m_doc.m_material_table.ModifyMaterial(new_mat, mat_index, true) )
          context.m_doc.Regen();
      }
    }
  }
 
  return IRhinoCommand.result.success;
}