LlCastRay Test
Purpose
Test the functionality of the llCastRay LSL command.
Sources
Scope
(Servers shipped sometime after May 2011)
Test Plan
Setup
none
norm and position correctness test
When you place this test script inside a perfect sphere, it casts ~10,200 rays from every direction, from 1m outside the sphere edge into the center of the sphere. This script reports the following error conditions:
Sim performance error (llCastRay() is disabled?) The ray didn't hit anything The ray hit a different object than the sphere The ray hit the sphere at wrong (>1mm error) coordinates The returned norm isn't the exact opposite of the ray cast direction
To run this test:
1) Rez a sphere of decently large size
2) Create the below script in it
3) Touch the sphere and wait for it to complete its computations. It will report any errors in llOwnerSay() chat.
4) Verify it does not report any errors.
default
{
touch_start(integer total_number)
{
vector my_pos=llGetPos();
vector my_scale=llGetScale();
float my_radius=my_scale.x/2; // assume this is a sphere
float scan_radius=my_radius+1.0; // how far away to be when casting rays
integer theta_resolution = 100; // scan in 100 parts
integer phi_resolution = 100; // scan in 100 parts
integer phi_index;
integer theta_index;
float phi;
float theta;
integer errors;
for(phi_index = 0; phi_index <= phi_resolution; phi_index++)
{
for(theta_index = 0; theta_index <= theta_resolution; theta_index++)
{
float theta = (theta_index * PI)/theta_resolution;
float phi = (phi_index * TWO_PI)/phi_resolution;
vector ray_start=my_pos;
ray_start.x += scan_radius * llSin(theta) * llCos(phi);
ray_start.y += scan_radius * llSin(theta) * llSin(phi);
ray_start.z += scan_radius * llCos(theta);
list hits = llCastRay(ray_start, my_pos, [RC_MAX_HITS, 1, RC_DATA_FLAGS, RC_GET_NORMAL]);
integer hit_result=llList2Integer(hits, -1); // how many objects we hit
string hit_message;
integer hit_index=0;
if(hit_result == RCERR_SIM_PERF_LOW)
{
++errors;
llOwnerSay("Error: RCERR_SIM_PERF_LOW @ "+(string)(ray_start-my_pos));
}
else if(hit_result == 0)
{
++errors; // we should always hit ourselves
llOwnerSay("Error: No hits @ "+(string)(ray_start-my_pos));
}
else
{
// hit something...
key hit_object=llList2Key(hits, hit_index);
vector hit_position=llList2Vector(hits, hit_index+1);
vector hit_normal=llList2Vector(hits, hit_index+2);
if(hit_object!=llGetKey())
{
++errors;
llOwnerSay("Error: Hit wrong object ("+ (string)hit_object +") @ "+(string)(ray_start-my_pos));
}
else
{
// hit ourselves
vector expected_hit_pos = my_pos + my_radius * < llSin(theta) * llCos(phi), llSin(theta) * llSin(phi), llCos(theta) >;
vector expected_hit_norm = llVecNorm(ray_start - my_pos);
if(expected_hit_norm * hit_normal < 0.99)
{
++errors;
llOwnerSay("Error: Unexpected norm @ "+(string)(ray_start-my_pos)+" Expected: "+(string)expected_hit_norm + " Got: "+(string)hit_normal);
}6.000
if( llVecDist(expected_hit_pos, hit_position) > 0.001 )
{
++errors;
llOwnerSay("Error: Unexpected hit pos @ "+(string)(ray_start-my_pos)+" Expected: "+(string)expected_hit_pos + " Got: "+(string)hit_position);
}
}
integer progress = (theta_index+1) + (phi_resolution+1)*phi_index;
llSetText("Completed " + (string)progress + "/" + (string)((phi_resolution+1)*(theta_resolution+1)) + "\n" + (string)errors + " errors", <1,1,1>, 1);
}
}
}
}
}
(test for mesh) This test also works on a 'mesh' sphere (e.g. a sphere prim with 50% hollow), although I found I had to loosen my accuracy tolerances quite a bit. For a 6m hollow sphere, the test passed when my hit-position tolerance was 15cm and the norm-direction tolerance was 0.9; much tighter values resulted in many "errors".
Multiple hits correctness test
This test verifies that the RC_MAX_HITS option works correctly, and that the list of hits is in the correct sequence.
1) Rez a box
2) Shift-copy the box 7 times along the x-axis
3) Rename the boxes "target1" through "target8", with the higher-indiced box being in the +x direction
4) Rez another box immediately to the west of 'target1'. Place this script inside the box:
integer max_hits;
integer options;
default
{
touch_start(integer total_number)
{
// RC_DATA_FLAGS options
options=RC_GET_ROOT_KEY|RC_GET_LINK_NUM;
vector mypos = llGetPos();
vector targetpos = mypos + <50, 0, 0>;
max_hits = (max_hits+1) % 8; // test 0-7 hits
//max_hits=256;
list hits = llCastRay(mypos, targetpos, [RC_MAX_HITS, max_hits, RC_DATA_FLAGS, options]);
//llSay(0, "raw output: "+llList2CSV(hits));
integer hit_result = llList2Integer(hits,-1);
string output = (string)max_hits + "max hits: ";
output += "hit "+(string)hit_result +" objects: ";
// by default, lLCastRay only returns the prim task_id and hit position.
// but if we ask it to return link number information, the stride increases
integer stride;
if(options & RC_GET_LINK_NUM)
{
stride=3;
}
else
{
stride=2;
}
integer i;
list hit_details;
for(i=0; i < llGetListLength(hits)-1; i+=stride)
{
key hit_object=llList2Key(hits,i);
vector hit_position;
integer hit_link;
if(stride==2)
{
hit_position = llList2Vector(hits,i+1);
hit_details += [llKey2Name(hit_object)+" @ "+(string)hit_position];
}
else
{
hit_link = llList2Integer(hits,i+1);
hit_position = llList2Vector(hits,i+2);
hit_details += [llKey2Name(hit_object)+" @ "+(string)hit_position + " link# " + (string)hit_link];
}
}
llSay(0, output + llList2CSV(hit_details));
}
}
5) Touch the scripted box 8 times. On the first touch, it should return information about target1 only, since llCastRay() stopped after 1 hit. On the 2nd touch, it should return details about target1 and target2. By the 7th touch, it should report information on the first 7 boxes. Verify that the data returned looks reasonable. Here's some example output:
[16:03] llCastRay max hits test: 1max hits: hit 1 objects: target1 @ <143.52390, 69.77858, 27.33796> link# 0 [16:03] llCastRay max hits test: 2max hits: hit 2 objects: target1 @ <143.52390, 69.77858, 27.33796> link# 0, target2 @ <146.02440, 69.77858, 27.33796> link# 0 [16:03] llCastRay max hits test: 3max hits: hit 3 objects: target1 @ <143.52390, 69.77858, 27.33796> link# 0, target2 @ <146.02440, 69.77858, 27.33796> link# 0, target3 @ <148.66260, 69.77858, 27.33796> link# 0 [16:03] llCastRay max hits test: 4max hits: hit 4 objects: target1 @ <143.52390, 69.77858, 27.33796> link# 0, target2 @ <146.02440, 69.77858, 27.33796> link# 0, target3 @ <148.66260, 69.77858, 27.33796> link# 0, target4 @ <151.51950, 69.77858, 27.33796> link# 0 [16:03] llCastRay max hits test: 5max hits: hit 5 objects: target1 @ <143.52390, 69.77858, 27.33796> link# 0, target2 @ <146.02440, 69.77858, 27.33796> link# 0, target3 @ <148.66260, 69.77858, 27.33796> link# 0, target4 @ <151.51950, 69.77858, 27.33796> link# 0, target5 @ <155.53380, 69.77858, 27.33796> link# 0 [16:03] llCastRay max hits test: 6max hits: hit 6 objects: target1 @ <143.52390, 69.77858, 27.33796> link# 0, target2 @ <146.02440, 69.77858, 27.33796> link# 0, target3 @ <148.66260, 69.77858, 27.33796> link# 0, target4 @ <151.51950, 69.77858, 27.33796> link# 0, target5 @ <155.53380, 69.77858, 27.33796> link# 0, target6 @ <159.84640, 69.77858, 27.33796> link# 0 [16:03] llCastRay max hits test: 7max hits: hit 7 objects: target1 @ <143.52390, 69.77858, 27.33796> link# 0, target2 @ <146.02440, 69.77858, 27.33796> link# 0, target3 @ <148.66260, 69.77858, 27.33796> link# 0, target4 @ <151.51950, 69.77858, 27.33796> link# 0, target5 @ <155.53380, 69.77858, 27.33796> link# 0, target6 @ <159.84640, 69.77858, 27.33796> link# 0, target7 @ <163.48640, 69.77858, 27.33796> link# 0 [16:03] llCastRay max hits test: Hit 0 objects: [16:03] llCastRay max hits test: 0max hits: hit 0 objects:
Technically, all single prim objects only have link #0, so these results are correct.
On the 8th touch, RC_MAX_HITS=0, which is invalid. The script should report this script error:
You must request at least one result from llCastRay.
6) Edit the script and set options=RC_GET_LINK_NUM, to disable RC_GET_ROOT_KEY. Repeat step (5), and verify that the data returned remains unchanged.
7) Shift-copy the 8 target boxes in the +y direction. Link each copy to its original prim, so that you now have 8 pairs of 2-prim objects. Append "root" to each of the root prim names, and append "child" to each of the child prim names.
8) Position the ray-casting object in front of the targetNchild prims, and repeat step (5), with options=RC_GET_LINK_NUM. Touch the box 8 times. In this case, llCastRay() should report the child prim names, and each hit should report "link #2".
9) Position the ray-casting object in front of the targetNchild prims, and repeat step (5), with options=RC_GET_LINK_NUM|RC_GET_ROOT_KEY. Touch the box 8 times. In this case, llCastRay() should report the root prim names, but each hit should report "link #2".
10) Position the ray-casting object in front of the targetNroot prims, and repeat step (5), with options=RC_GET_LINK_NUM|RC_GET_ROOT_KEY. Touch the box 8 times. In this case, llCastRay() should report the root prim names, but each hit should report "link #1".
11) Position the ray-casting object in front of the targetNroot prims, and repeat step (5), with options=RC_GET_LINK_NUM. Touch the box 8 times. In this case, llCastRay() should report the same results as in (10).