Thread: is it possible to draw the ray D3DXIntersect creates?

You would have to create a primitive using the ray. Using the parametric form you should be able to cast a ray using the info from D3DXIntersect and a set distance.

Sure it can. Given a 3D vector and a distance:

Code:

#ifndef VERTEX_H
#define VERTEX_H

struct  Vertex
{
  float x,y,z;
  float u,v;
 
  Vertex():x(0.0f),y(0.0f),z(0.0f),u(0.0f),v(0.0f) { }
  Vertex(float x,float y,float z,float u, float v):x(x),y(y),z(z),u(u),v(v) { }

  static const DWORD FVF;
};

#endif

Code:

#include "Vertex.h"

const DWORD Vertex::FVF = D3DFVF_XYZ | D3DFVF_TEX1;

Vertex Vertices[4];

void CreateVerticesFromRay(D3DXVECTOR3 vecRay, float dist)
{
  D3DXVec3Normalize(&vecRay,&vecRay);

  Vertices[0]  = Vertex(0.0f,0.0f,0.0f,0.0f,0.0f);
  Vertices[1] = Vertex(vecRay.x * dist,0.0f,0.0f,1.0f,0.0f);
  Vertices[2] = Vertex(0.0f,0.0f,vecRay.z * dist,0.0f,1.0f);
  Vertices[3] = Vertex(vecRay.x * dist,0.0f, vecRay.z * dist,1.0f,1.0f);

}

What do you mean you cannot draw a primitive on the z axis?

That's not much help. Post some code and I can help fix it. Incorrect rendering can be caused by incorrect projection matrices, incorrect translation/rotation/scaling/shearing, etc, etc matrices and so on. There are an inumerable about issues that could be happening. Guessing won't help you any so post the code that's drawing the line and setting the system up.