3 replies to this topic

[porters]

Hi,

Basically i'm trying to create a custom vertex and use it in my vertex shader. The vertex is simply a standard position colored vertex, but i want to add an integer value as well. I cant seem to figure out what vertexformat and vertex semantic to use for this integer value. I've tried using the pointsize and blendindices formats/semantics, but the shader doesnt seem to recognize any value a set for scale.

How can i use an integer value in my custom vertex?

Heres an example of my vertex structure as defined in my program (VB.Net):

<System.Runtime.InteropServices.StructLayout(Runtime.InteropServices.LayoutKind.Sequential)> _
			Public Structure PositionColoredScale
				Public Position As Vector3
				Public Color As Integer
				Public Scale As Integer
				Public Shared ReadOnly Format As VertexFormat = VertexFormat.Position Or VertexFormat.Diffuse Or VertexFormat.None
				Public Shared ReadOnly Property SizeInBytes() As Integer
					Get
						Return System.Runtime.InteropServices.Marshal.SizeOf(GetType(PositionColoredScale))
					End Get
				End Property
			End Structure

Here's the structure in my shader:

struct VSInputVcScl
{
float4 Position : POSITION;
float4 Color  : COLOR;
uint Scale : BLENDINDICES0;
};

Thanks guys.

[Jeason]

How about using float in the struct and then cast to int in shader if you don't care the speed hit?

[porters]

I could do that, but i dont see how that solves my problem. I'm after the correct semantic/vertex format to use for passing an arbitary integer (or a float) value to the shader. I want the GPU to ignore this value, it will only be used by me in some calculations.

[Jeason]

I think there may be something wrong at other places.

Additionally,I find D3DFVF_SPECULAR is DWORD, but i haven' never used.