Raycast Visualizer

[Wulfie Reanimator]

This script is intended to help show exactly where the ray travels and what it hits, if anything.
All you need to do is manually adjust the visualizer's position and rotation using the build tools, and touch the object to "fire" a ray.
The length of the ray can be adjusted by saying any length in local chat, and the visualizer will adjust to it.

To get set up, rez 3 (of any) prims, link them together, and then put this script in. It will create an object like this:

And here it is in action, hitting the inside of a hollow sphere:

Here's the code:

float length = 5;

default
{
    state_entry()
    {
        // This simply sets up the object properly.
        // Link 1 and 3 are spheres, link 2 is the long cylinder.
        llSetLinkPrimitiveParamsFast(1,[
            9, 3, 0, <0,1,0>, 0.0, <0,0,0>, <0,1,0>,
                18, -1, <0.251,0,1>, 0.5, 7, <0.2,0.2,0.2>,
            34, 2, 33, <0,0,0>, 9, 1, 0, <0,1,0>, 0.0, <0,0,0>, <1,1,0>, <0,0,0>,
                18, -1, <1,0,0.251>, 1, 7, <0.01,0.01,10>, 35, <0.4950,1,0>, 30, 1,
            34, 3, 33, <0,0,0>, 9, 3, 0, <0,1,0>, 0.15, <0,0,0>, <0,1,0>,
                18, -1, <0.251,0,1>, 0.5, 7, <0.2,0.2,0.2>, 30, 1
        ]);
        
        // Only listen to the owner's avatar.
        llListen(0, "", llGetOwner(), "");
    }
    
    listen(integer c, string n, key id, string m)
    {
        // Only react to valid floats.
        if( ((float)(m+"1") == 0.0) ) return;
        
        length = (float)m;
        llSetLinkPrimitiveParamsFast(2, [PRIM_SIZE, <0,0,length*2>]);
        llOwnerSay("New length set.");
    }

    touch_start(integer n)
    {
        // Rotate the end-position of the ray with the object.
        list data = llCastRay( llGetPos(),
            llGetPos() + ((<0,0,length>) * llGetRot()),
            [RC_DATA_FLAGS, RC_GET_ROOT_KEY | RC_GET_LINK_NUM]);
        
        if(llList2Integer(data, -1)) // Was there a hit?
        {
            llOwnerSay("Raycast hit \"" + llKey2Name(llList2Key(data, 0)) +
            "\" link #" + llList2String(data, 1));
            
            // "Dividing" the position with the object's own rotation removes the rotation.
            llSetLinkPrimitiveParamsFast(3,
                [PRIM_POS_LOCAL, (llList2Vector(data, 2) - llGetPos()) / llGetRot()]);
        }
        else
        {
            llOwnerSay("Nothing was hit.");
            llSetLinkPrimitiveParamsFast(3, [PRIM_POS_LOCAL, <0,0,length>]);
        }
    }
}

 

Edited March 25, 2018 by Wulfie Reanimator

[Xiija]

Works good