This is my first post here so any help would be massively appreciated :)

I'm using C++ with SDL and OpenGL 3.3

When rendering directly to screen I get the following result

And when I render to texture I this happens

Anti-aliasing is turned off for both. I'm guessing this has something to do with depth buffer accuracy but I've tried a lot of different methods to improve the result but, no success :( I'm currently using the following code to set up my FBO:

GLuint frameBufferID;
glGenFramebuffers(1, &frameBufferID);
glBindFramebuffer(GL_FRAMEBUFFER, frameBufferID);

glGenTextures(1, &coloursTextureID);

glBindTexture(GL_TEXTURE_2D, coloursTextureID);
glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,SCREEN_WIDTH,SCREEN_HEIGHT,0,GL_RGB,GL_UNSIGNED_BYTE,NULL);

glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);



//Depth buffer setup

GLuint depthrenderbuffer;
glGenRenderbuffers(1, &depthrenderbuffer);
glBindRenderbuffer(GL_RENDERBUFFER, depthrenderbuffer);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, SCREEN_WIDTH,SCREEN_HEIGHT);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthrenderbuffer);


glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, coloursTextureID, 0);

GLenum DrawBuffers[1] = {GL_COLOR_ATTACHMENT0};
glDrawBuffers(1, DrawBuffers); // 

if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
        return false;

Thank you so much for any help :)