Hi Guys,

I have flat geometry in my game (sort of a 2.5D style concept) and I am wondering, is it possible create a vertex buffer that uses x, y positions only. So, each vertex is a total of 8 bytes instead of 12?

If this is possible, can I then still translate the z axis via the shader so it can still be positioned in 2D space?

My geometry is pretty vertex heavy and if this is possible, I'll be able to cut down the geometry by discarding the un-used z position (as it is always zero).

Thanks in advance :)

Nice, thanks guys. +1 to you both

cbuffer Parameters
{
    uint Subdivisions;
    matrix WVP;
}

void VS(uint vid : SV_VertexID, out float2 tex : TEXCOORD, out float4 posh: SV_POSITION)
{
    float x = vid % (Subdivisions + 1);
    float y = vid / (Subdivisions + 1);
    tex = float2(x,y) / Subdivisions;
    posh = mul(float4(tex, 0, 1), WVP);
}

Ala vertex shader tricks you can determine the coordinates through the index buffer alone, no need for a vertex buffer

cbuffer Parameters
{
    uint Subdivisions;
    matrix WVP;
}

void VS(uint vid : SV_VertexID, out float2 tex : TEXCOORD, out float4 posh: SV_POSITION)
{
    float x = vid % (Subdivisions + 1);
    float y = vid / (Subdivisions + 1);
    tex = float2(x,y) / Subdivisions;
    posh = mul(float4(tex, 0, 1), WVP);
}

Edit: This assumes a uniform grid or at least discrete coordinates ( (0,0), (0,1), (0,2) etc.).

Sorry, I'm not understanding what this does or how this relates to creating models using just x & y co-ordinates.

Ah ok, I think we are thinking along different lines. Are you talking about quads and then mapping textures to them?

In my case, I am creating geometry along the lines of SVG's, so I am not using quad's or textures. Pure vertices to convey the scene.

Oh, well, in that case: Sorry. L.Spiro's post led me to believe we are talking about height map patches. Reading helps . So no, this has no use for you I think.

Oh, well, in that case: Sorry. L.Spiro's post led me to believe we are talking about height map patches. Reading helps . So no, this has no use for you I think.

Hehe, no worries :)

Thanks for the link though, it looks like it has some very useful info in there :)