How to use glm::project to get the coordinates of a point in world space?
<p>I have a point (1, 2) in 2D space that I expressed as a vector:</p>

<pre><code>glm::vec3 pt = glm::vec3(1, 2, 0)
</code></pre>

<p>(here I set the third component to 0 - not sure if that's correct?)</p>

<p>I have a model-view matrix to apply a translation to the point:</p>

<pre><code>glm::mat4 ModelView = glm::mat4(1.0f);
ModelView = glm::translate(ModelView, glm::vec3(3.0f, 3.0f, 0.0f));
</code></pre>

<p>Now I want to find the actual coordinate of the point in world space. I did some research and <code>glm::project()</code> seems to be something that I can use for this. It takes in 4 parameters:</p>

<pre><code>detail::tvec3&lt;T&gt; glm::gtc::matrix_transform::project(detail::tvec3&lt;T&gt; const &amp; obj,
                                                     detail::tmat4x4&lt;T&gt; const &amp; model,
                                                     detail::tmat4x4&lt;T&gt; const &amp; proj,
                                                     detail::tvec4&lt;U&gt; const &amp; viewport 
)
</code></pre>

<p>The first two parameters are the point and the model view matrix which I already have. However what should I use for the 3rd and 4th parameters (the projection matrix and viewport vector)? How can I create/get them?</p>