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Help with 3D cube coordinates

Started by elendil67 Jan 4, 2003 at 8:48 PM 7 replies 1.4k views

Original Post

Jan 4, 2003 at 8:48 PM

Hi there. I am making a cube from triangle lists (no indices yet), but I can't get it right or find the coordinates for a cube. Some faces show up unlit, but others show up strangely, and yet others don't show up at all. I am very confused. Do you know what I might be doing wrong? My custom vertex has the three X, Y, Z position floats followed by three X, Y, Z normal floats. You can find the whole source here.

      
vertex_t vertices[36] = 
{
    // Top face

    //  X      Y      Z      NX     NY     NZ

    { -1.0f,  1.0f, -1.0f,  0.0f,  1.0f,  0.0f },
    { -1.0f,  1.0f,  1.0f,  0.0f,  1.0f,  0.0f },
    {  1.0f,  1.0f,  1.0f,  0.0f,  1.0f,  0.0f },
    { -1.0f,  1.0f, -1.0f,  0.0f,  1.0f,  0.0f },
    {  1.0f,  1.0f,  1.0f,  0.0f,  1.0f,  0.0f },
    {  1.0f,  1.0f, -1.0f,  0.0f,  1.0f,  0.0f },

    // Front face

    //  X      Y      Z      NX     NY     NZ

    { -1.0f, -1.0f, -1.0f,  0.0f,  0.0f, -1.0f },
    { -1.0f,  1.0f, -1.0f,  0.0f,  0.0f, -1.0f },
    {  1.0f,  1.0f, -1.0f,  0.0f,  0.0f, -1.0f },
    { -1.0f, -1.0f, -1.0f,  0.0f,  0.0f, -1.0f },
    {  1.0f,  1.0f, -1.0f,  0.0f,  0.0f, -1.0f },
    {  1.0f, -1.0f, -1.0f,  0.0f,  0.0f, -1.0f },

    // Left face

    //  X      Y      Z      NX     NY     NZ

    { -1.0f, -1.0f,  1.0f, -1.0f,  0.0f,  0.0f },
    { -1.0f,  1.0f,  1.0f, -1.0f,  0.0f,  0.0f },
    { -1.0f,  1.0f, -1.0f, -1.0f,  0.0f,  0.0f },
    { -1.0f, -1.0f,  1.0f, -1.0f,  0.0f,  0.0f },
    { -1.0f,  1.0f, -1.0f, -1.0f,  0.0f,  0.0f },
    { -1.0f, -1.0f, -1.0f, -1.0f,  0.0f,  0.0f },

    // Right face

    //  X      Y      Z      NX     NY     NZ

    {  1.0f, -1.0f,  1.0f,  1.0f,  0.0f,  0.0f },
    {  1.0f,  1.0f,  1.0f,  1.0f,  0.0f,  0.0f },
    {  1.0f,  1.0f, -1.0f,  1.0f,  0.0f,  0.0f },
    {  1.0f, -1.0f,  1.0f,  1.0f,  0.0f,  0.0f },
    {  1.0f,  1.0f, -1.0f,  1.0f,  0.0f,  0.0f },
    {  1.0f, -1.0f, -1.0f,  1.0f,  0.0f,  0.0f },

    // Back face

    //  X      Y      Z      NX     NY     NZ

    { -1.0f, -1.0f,  1.0f,  0.0f,  0.0f,  1.0f },
    { -1.0f,  1.0f,  1.0f,  0.0f,  0.0f,  1.0f },
    {  1.0f,  1.0f,  1.0f,  0.0f,  0.0f,  1.0f },
    { -1.0f, -1.0f,  1.0f,  0.0f,  0.0f,  1.0f },
    {  1.0f,  1.0f,  1.0f,  0.0f,  0.0f,  1.0f },
    {  1.0f, -1.0f,  1.0f,  0.0f,  0.0f,  1.0f },

    // Bottom face

    //  X      Y      Z      NX     NY     NZ

    { -1.0f, -1.0f, -1.0f,  0.0f, -1.0f,  0.0f },
    { -1.0f, -1.0f,  1.0f,  0.0f, -1.0f,  0.0f },
    {  1.0f, -1.0f,  1.0f,  0.0f, -1.0f,  0.0f },
    { -1.0f, -1.0f, -1.0f,  0.0f, -1.0f,  0.0f },
    {  1.0f, -1.0f,  1.0f,  0.0f, -1.0f,  0.0f },
    {  1.0f, -1.0f, -1.0f,  0.0f, -1.0f,  0.0f },
};

[ c o d e m a t r i x ] [edited by - elendil67 on January 4, 2003 9:53:11 PM]

elendil67

Jan 5, 2003 at 1:23 PM

Anyone?

[ c o d e m a t r i x ]

Pipo DeClown

Jan 5, 2003 at 2:28 PM

Try swapping the ZNormals from the front and the back face.
So the fronts become positive and the backs negative.

elendil67

Jan 5, 2003 at 4:33 PM

Thanks but that doesn''t work either.

[ c o d e m a t r i x ]

Gladiator

Jan 5, 2003 at 4:37 PM

Make sure you use one of the hand rules for defining the object''s vertices ( i.e. Left hand rule and Right hand rule ) and stick to it throughout.

Hoff

Jan 5, 2003 at 4:41 PM

It looks like your triangles aren''t consistently wound the same way. When viewed from the front, all vertices should go either clockwise or counter-clockwise.

-- John

elendil67

Jan 5, 2003 at 5:29 PM

Strange. I took a long time to try and wind them counter-clockwise. Do you know if I did anything wrong with winding them? Thanks.

[ c o d e m a t r i x ]

elendil67

Jan 6, 2003 at 6:43 PM

Anyone? Wow, it''s like exactly 24 hours between posts... veird

[ c o d e m a t r i x ]

luxitan

Jan 7, 2003 at 5:16 AM

try using this lpDXDev->SetRenderState( D3DRS_CULLMODE, D3DCULL_NONE );
so see if all your faces are beeing drawn, what this does is draw a face clockwise or counter-clockwise

then use this lpDXDev->SetRenderState(D3DRS_FILLMODE, D3DFILL_WIREFRAME); to see if your trangle are well designed

hope it helps

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