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[MDX] Create a vertex buffer

Started by simotix Jul 6, 2008 at 12:11 AM 6 replies 1.9k views

Original Post

Jul 6, 2008 at 12:11 AM

I am creating a vertex buffer with a custom format and I am not sure how to set the vertex format. Does anyone know how? Right now I am just setting " CustomVertex.PositionTextured.Format" as a temporary one. The reason I ask is because I get this error when I try to call new VertexBuffer on my VertexBuffer. An unhandled exception of type 'System.InvalidOperationException' occurred in Microsoft.DirectX.dll Additional information: Operation is not valid due to the current state of the object. Vertex Buffer Creation


            D3D.VertexElement[] dvVertexElements = new D3D.VertexElement[]
            {
                new VertexElement(0, 0, DeclarationType.Float3, DeclarationMethod.Default, DeclarationUsage.Position, 0),
                new VertexElement(0, 12, DeclarationType.Float3, DeclarationMethod.Default, DeclarationUsage.Normal, 0),
                new VertexElement(0, 24, DeclarationType.Float2, DeclarationMethod.Default, DeclarationUsage.TextureCoordinate, 0),

                D3D.VertexElement.VertexDeclarationEnd

            };

            VertexDeclaration = new VertexDeclaration(pDevice, dvVertexElements);

            // indexed square data
            tShapeVertex[] shapeVerticies = new tShapeVertex[8];

            // Front
            shapeVerticies[0] = new tShapeVertex(0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -1.0f, -fUOffset, -fVOffset, 0.0f, 0.0f, 0.0f, 0.0f);	// Front Bottom Left
            shapeVerticies[1] = new tShapeVertex(0.0f, fHeight, 0.0f, 0.0f, 0.0f, -1.0f, -fUOffset, fV, 0.0f, 0.0f, 0.0f, 0.0f);	// Front Upper Left
            shapeVerticies[2] = new tShapeVertex(fWidth, fHeight, 0.0f, 0.0f, 0.0f, -1.0f, fU, fV, 0.0f, 0.0f, 0.0f, 0.0f);	// Front Upper Right
            shapeVerticies[3] = new tShapeVertex(fWidth, 0.0f, 0.0f, 0.0f, 0.0f, -1.0f, fU, -fVOffset, 0.0f, 0.0f, 0.0f, 0.0f);	// Front Bottom Right

            if (bTwoSided == true)
            {
                // Back
                shapeVerticies[4] = new tShapeVertex(0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, -fUOffset, -fVOffset, 0.0f, 0.0f, 0.0f, 0.0f);	// Bottom Left
                shapeVerticies[5] = new tShapeVertex(fWidth, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, -fU, -fVOffset, 0.0f, 0.0f, 0.0f, 0.0f);	// Bottom Right
                shapeVerticies[6] = new tShapeVertex(fWidth, fHeight, 0.0f, 0.0f, 0.0f, 1.0f, -fU, -fV, 0.0f, 0.0f, 0.0f, 0.0f);	// Upper Right
                shapeVerticies[7] = new tShapeVertex(0.0f, fHeight, 0.0f, 0.0f, 0.0f, 1.0f, -fUOffset, -fV, 0.0f, 0.0f, 0.0f, 0.0f);	// Upper Left
                VertCount = 8;
            }

            int[] indices = new int[12];
            int nIndicies = 6;

            // Front
            indices[0] = 0; indices[1] = 1; indices[2] = 2;
            indices[3] = 0; indices[4] = 2; indices[5] = 3;
            TriCount = 2;
            nIndicies = 6;

            if (bTwoSided == true)
            {
                // Back
                indices[6] = 4; indices[7] = 5; indices[8] = 6;
                indices[9] = 4; indices[10] = 6; indices[11] = 7;
                TriCount = 4;
                nIndicies = 12;
            }

            // create vertex buffer
            VertexBuffer = new VertexBuffer(typeof(tShapeVertex), 8, pDevice, Usage.WriteOnly, CustomVertex.PositionTextured.Format, Pool.Default);
            VertexBuffer.SetData(shapeVerticies, 0, LockFlags.None);

            // create index buffer
            IndiceBuffer = new IndexBuffer(typeof(int), nIndicies, pDevice, Usage.WriteOnly, Pool.Default);
            IndiceBuffer.SetData(indices, 0, LockFlags.None);

Custom Vertex Structure


using System;
using System.Collections.Generic;
using System.Text;

namespace WorldEditor.Engine.Shapes
{
    class tShapeVertex
    {
       // tShapeVertex() { }
        public tShapeVertex(float x, float y, float z,
            float nx, float ny, float nz, float u, float v, float t1, float t2, float t3, float t4)
        {
            _x = x; _y = y; _z = z;
            _nx = nx; _ny = ny; _nz = nz;
            _u = u; _v = v; _t1 = t1;
            _t2 = t2; _t3 = t3; _t4 = t4;
        }

        float _x, _y, _z, _nx, _ny, _nz, _u, _v, _t1, _t2, _t3, _t4;

    };

}

Mike.Popoloski

Jul 6, 2008 at 7:14 AM

I had a hunch about what the problem might be, and a quick look around with Reflector confirmed it. You cannot create a vertex buffer using reference type vertices (ie classes). You need value type vertices. It's not a very descriptive error message actually.

simotix

Jul 6, 2008 at 9:41 AM

You were correct, I changed my custom vertex type to a struct it and does compile. However, what about for what I put as the VertexFormat parameter? What should really be there since I am using a custom vertex format?

Mike.Popoloski

Jul 6, 2008 at 9:46 AM

Quote:
Original post by simotix
You were correct, I changed my custom vertex type to a struct it and does compile. However, what about for what I put as the VertexFormat parameter? What should really be there since I am using a custom vertex format?

You should put null since you are using vertex declarations. A vertex format is only necessary when doing FFP (fixed function pipeline) work.

simotix

Jul 6, 2008 at 10:36 AM

I am doing programmable pipeline work, however, I do not get any textures to show on my object. I know they are all loading and everything because I use to creat everything as a mesh and recently converted to vertex buffers (since it is just a smarter thing to do). I updated a few things, one of them being the vertex decleration since I noticed I was not putting in everything. Also, I could not just set VertexFormat to null, I had to set it to VertexFormat.None. Do you notice anything wrong with the current code? The shape does render, however, there is just no texture on it.

D3D.VertexElement[] dvVertexElements = new D3D.VertexElement[]            {                new VertexElement(0, 0, DeclarationType.Float3, DeclarationMethod.Default, DeclarationUsage.Position, 0),                new VertexElement(0, 12, DeclarationType.Float3, DeclarationMethod.Default, DeclarationUsage.Normal, 0),                new VertexElement(0, 24, DeclarationType.Float2, DeclarationMethod.Default, DeclarationUsage.TextureCoordinate, 0),                new VertexElement(0, 32, DeclarationType.Float4, DeclarationMethod.Default, DeclarationUsage.Tangent, 0),                D3D.VertexElement.VertexDeclarationEnd            };            VertexDeclaration = new VertexDeclaration(pDevice, dvVertexElements);            // indexed square data            tShapeVertex[] shapeVerticies = new tShapeVertex[8];            // Front            shapeVerticies[0] = new tShapeVertex(0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -1.0f, -fUOffset, -fVOffset, 0.0f, 0.0f, 0.0f, 0.0f);	// Front Bottom Left            shapeVerticies[1] = new tShapeVertex(0.0f, fHeight, 0.0f, 0.0f, 0.0f, -1.0f, -fUOffset, fV, 0.0f, 0.0f, 0.0f, 0.0f);	// Front Upper Left            shapeVerticies[2] = new tShapeVertex(fWidth, fHeight, 0.0f, 0.0f, 0.0f, -1.0f, fU, fV, 0.0f, 0.0f, 0.0f, 0.0f);	// Front Upper Right            shapeVerticies[3] = new tShapeVertex(fWidth, 0.0f, 0.0f, 0.0f, 0.0f, -1.0f, fU, -fVOffset, 0.0f, 0.0f, 0.0f, 0.0f);	// Front Bottom Right            // Back            shapeVerticies[4] = new tShapeVertex(0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, -fUOffset, -fVOffset, 0.0f, 0.0f, 0.0f, 0.0f);	// Bottom Left            shapeVerticies[5] = new tShapeVertex(fWidth, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, -fU, -fVOffset, 0.0f, 0.0f, 0.0f, 0.0f);	// Bottom Right            shapeVerticies[6] = new tShapeVertex(fWidth, fHeight, 0.0f, 0.0f, 0.0f, 1.0f, -fU, -fV, 0.0f, 0.0f, 0.0f, 0.0f);	// Upper Right            shapeVerticies[7] = new tShapeVertex(0.0f, fHeight, 0.0f, 0.0f, 0.0f, 1.0f, -fUOffset, -fV, 0.0f, 0.0f, 0.0f, 0.0f);	// Upper Left            VertCount = 8;            int[] indices = new int[12];            int nIndicies = 6;            // Front            indices[0] = 0; indices[1] = 1; indices[2] = 2;            indices[3] = 0; indices[4] = 2; indices[5] = 3;            TriCount = 2;            nIndicies = 6;            // Back            indices[6] = 4; indices[7] = 5; indices[8] = 6;            indices[9] = 4; indices[10] = 6; indices[11] = 7;            TriCount = 4;            nIndicies = 12;            // create vertex buffer            VertexBuffer = new VertexBuffer(typeof(tShapeVertex), 8, pDevice, Usage.WriteOnly, VertexFormats.None, Pool.Default);            VertexBuffer.SetData(shapeVerticies, 0, LockFlags.None);            // create index buffer            IndiceBuffer = new IndexBuffer(typeof(int), nIndicies, pDevice, Usage.WriteOnly, Pool.Default);            IndiceBuffer.SetData(indices, 0, LockFlags.None);

My actual render code looks like this, the only thing I thought I needed to set was the vertex buffer.

                ptrDevice.VertexFormat = VertexFormats.None;                ptrDevice.SetStreamSource(0, planeList.VertexBuffer, 0);                BasicTextureEffect.CommitChanges();                planeList.Render(ptrDevice);   .... Render            pDevice.Indices = IndiceBuffer;            pDevice.DrawIndexedPrimitives(PrimitiveType.TriangleFan, 0, 0, VertCount, 0, TriCount);

Mike.Popoloski

Jul 6, 2008 at 10:41 AM

You don't appear to be setting the vertex declaration anywhere. If you are and just haven't shown it, then I would guess that there is something wrong with your vertex shader and/or pixel shader.

Promit

Jul 6, 2008 at 12:09 PM

Quick sidenote -- in building your vertex declaration, you should probably use Marshal.OffsetOf to ensure that the offsets you pass to D3D are correct. Probably not related to your problem, though.

simotix

Jul 6, 2008 at 12:31 PM

Mike.Popoloski, you were correct. For some reason I forgot to do that. Thank you for the help.

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