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# OpenGL OpenGL won't render anything

## 4 posts in this topic

I'm writing a basic OpenGL framework in C# and I've got a problem that is holding me for 3 days.

I've managed to create the window, OpenGL context and all necessary things using OpenTK.

I can also clear the screen using glClear/glClearColor, but I can't render anything.

As I'm using an OpenTK assembly built with DEBUG any OpenGL error that I could get would be catch by OpenTK and a exception would be thrown but there are no errors.

I've working on this for 3 days and I have no clue of what is the problem. If someone need any piece of code to help me, just ask.

[spoiler]

#version 330

in vec3 iPosition;
in vec3 iNormal;
in vec4 iColor;

out vec4 gColor;

uniform mat4 WorldViewProjection;

void main()
{
gColor = iColor;
gl_Position = WorldViewProjection * vec4(iPosition, 1);
}



[/spoiler]

[spoiler]

in vec4 gColor;

uniform float Alpha;

out vec4 OutFragColor;

void main()
{
OutFragColor = vec4(1,1,1,1);
} 

[/spoiler]

Test Vertices:

[spoiler]

0.75f, 0.75f, 0.0f

0.75f, -0.75f, 0.0f

-0.75f, -0.75f, 0.0f

[/spoiler]

This would be a closed source engine but I'm pushing the code on GitHub so someone could help: https://github.com/GreenBoxDevelopment/gb3d

Some important files:

Test/SimpleTest/TestApp/TestGame.cs
Source/Engine/GreenBox3D/Graphics/*
Source/Engine/Platform/GreenBox3D.Platform.Windows/Graphics/*


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I didn't look all of the code but have you tried changing the order of those vertices? Maybe your winding is incorrect? And I'm not sure but seems like you're using a lookat matrix for the modelviewprojection uniform, where's the projection?

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I'll take a look at the winding, about the matrix I already tried several others, including without a matrix as those vertices would work w/o one.

As I took that vertices from http://www.arcsynthesis.org/gltut/ I assume that they work

Edited by greenboxal
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Winding is probably not it - if you don't specifically enable backface culling, it's not on. What I'd try is first negative z values for the vertices and then ditching the matrix multiplication to see if the matrix is really okay.

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Tried all kind of modification on the vertices, the matrix code is supposed to be okay as it is part of OpenTK and they work there. Also tried transposing the matrix when sending it to the shaders but it didn't work.

[hr]

Fixed: I forgot to set the Viewport as the default one isn't compatible with my window creation code, I'm dumb x.x

Edited by greenboxal
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