CODEWITHSUNDEEP
c++renderingintersectionraytracing
Bhargav B
Bhargav B

Reputation: 131

Raytracer won't render more than one instance of an object

I'm writing a raytracer in C++ and I'm having quite a bit of trouble understanding why my output images don't contain all of the objects that should be there. Namely, I'm working with spheres and planes, and I can't draw more than one instance of each.

The object values are read in from an ASCII file (such as radius, location, normals, etc). Here's my intersect test code.

//check primary ray against each object
    for(int size = 0; size < objList.size(); size++){
      //if intersect
      if(objList[size]->intersect(ray,origin,&t)){
        if(t < minDist){ //check depth
          minDist = t; //update depth
          bestObj = size; //update closest object
        }
      }
    }
    vec3 intersection = origin + minDist*ray;

//figure out what to draw, if anything
    color_t shadeColor;
    if(bestObj != -1){ //valid object
      //get base color
      //using rgb color
      if(objList[bestObj]->rgbColor != vec3(-1)){
        shadeColor.r = objList[bestObj]->rgbColor.x;
        shadeColor.g = objList[bestObj]->rgbColor.y;
        shadeColor.b = objList[bestObj]->rgbColor.z;
      }
      //else using rgbf color
      else if(objList[bestObj]->rgbfColor != vec4(-1)){
        shadeColor.r = objList[bestObj]->rgbfColor.x;
        shadeColor.g = objList[bestObj]->rgbfColor.y;
        shadeColor.b = objList[bestObj]->rgbfColor.z;
        //need to do something with alpha value
      }
      //else invalid color
      else{
        cout << "Invalid color." << endl;
      }

//...the rest is just shadow and reflection tests. There are bugs here as well, but those are for another post

The above code is within a loop that checks for every pixel. 'ray' is the direction of the ray, and 'origin' is the origin of that ray. 'objList' is an stl vector that holds each object in the scene. I've tested to make sure that each object is actually getting put into the vector.

I know that my intersection tests are working...at least for the one object of each type that renders. I've had the program print to a file all the values that 'bestObj' ever gets, but it never seems to register that any of the objects other than the last one is a 'bestObj'. I realize that this is the problem, that no other object gets set as the 'bestObj', but I can't figure out why!

Any help would be appreciated :)

Upvotes: 0

Views: 189

Answers (1)

Bhargav B
Bhargav B

Reputation: 131

I figured out the problem, thanks to didierc. I'm not sure what he was really talking about, but it made me think about how I was handling my pointers. Indeed, though my vector was pushing back every object, I wasn't creating new objects for each time I pushed one back. This led to each sphere in the stl vector pointing to the same one (aka the last one read in from file)!

Upvotes: 0

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