Assimp Loading Issue (WIP)

I am going absolutely insane.

C++ Mesh Drawing code:

void Mesh::draw(const Shader& shader)
{
	unsigned int diffuseNumber = 1;
	unsigned int specularNumber = 1;
	unsigned int normalNumber = 1;
	unsigned int heightNumber = 1;

	for (unsigned int i = 0; i < textures.size(); ++i)
	{
		glActiveTexture(GL_TEXTURE0 + i);

		std::string number;
		const std::string name = textures[i].type;

		// TODO
		// hard-coded but whatever for now
		if (name == "texture_diffuse")  number = std::to_string(diffuseNumber++);
		else if (name == "texture_specular") number = std::to_string(specularNumber++);
		else if (name == "texture_normal")   number = std::to_string(normalNumber++);
		else if (name == "texture_height")   number = std::to_string(heightNumber++);

		std::string address("material.");
		address.append(name).append(number);
		shader.set(address, i);

		glBindTexture(GL_TEXTURE_2D, textures[i].id);
	}

	// Draw Mesh / Pipe-in bound information
	glBindVertexArray(_vao);
	glDrawElements(GL_TRIANGLES, indices.size(), GL_UNSIGNED_INT, 0);

	glBindVertexArray(0);
	//glActiveTexture(GL_TEXTURE0);
}

---

Situation 1: Use everything as per default (pass in unsigned integer for texture ID)

GLSL Display diffuse:

fragmentColor = texture(material.texture_diffuse1, textureCoordinate);

GLSL Display specular (and basically everything else):

fragmentColor = texture(material.texture_specular1, textureCoordinate);

---

Situation 2: Pass in signed integer instead.

Changes to C++ code from above:

shader.set(address, (int)i);

Diffuse:

fragmentColor = texture(material.texture_diffuse1, textureCoordinate);

Cool, so that works.

Specular:

fragmentColor = texture(material.texture_specular1, textureCoordinate);