# Completely red screen in Chapter 2 after changing to .point

**URL:** <https://forums.kodeco.com/t/completely-red-screen-in-chapter-2-after-changing-to-point/155549>\
**Category:** Metal by Tutorials\
**Created:** [November 1, 2021, 9:19am UTC](https://forums.kodeco.com/t/completely-red-screen-in-chapter-2-after-changing-to-point/155549 "2021-11-01T09:19:23Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![caroline](https://assets.chunter.kodeco.com/user_avatar/forums.kodeco.com/caroline/32/111867_2.png) [@caroline](https://forums.kodeco.com/u/caroline)\
**Post date:** [November 1, 2021, 10:55am UTC](https://forums.kodeco.com/t/completely-red-screen-in-chapter-2-after-changing-to-point/155549/2 "2021-11-01T10:55:54Z")

</div>

Hi @makoren and welcome to the forum!

Unfortunately Apple changed the default size of a “point”.

In Chapter 2 playground, you can change the shader code to this:

```auto
let shader = """
#include <metal_stdlib>
using namespace metal;
struct VertexIn {
float4 position [[attribute(0)]];
};
struct VertexOut {
float4 position [[position]];
float pointSize [[point_size]];
};
vertex VertexOut vertex_main(const VertexIn vertex_in [[stage_in]]) {
VertexOut out {
.position = vertex_in.position,
.pointSize = 5
};
return out;
}
fragment float4 fragment_main() {
return float4(1, 0, 0, 1);
}
"""

```

Here, instead of just returning the vertex position from the vertex shader, you’re creating a structure `VertexOut` which holds both the position and the specified point size.

You’ll be creating structures very shortly to return from shaders. This is more common than just returning a `float4` `position`.

At the beginning of learning Metal, you’ll probably get the feeling that you need to know something before you tackle something else, and you haven’t learned that something yet. There is a lot to get your head around in the beginning, but if you stick with it, you’ll find after a few chapters of repeating creating shaders and passing around vertices, that it all falls into place.

---

_[View the full topic](https://forums.kodeco.com/t/completely-red-screen-in-chapter-2-after-changing-to-point/155549)._