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1

Off Topic / Spongeb

« on: March 01, 2021, 02:51:21 PM »

Post the greatest redditbob moments of all time For me it's https://www.youtube.com/watch?v=VUqazy_ohiw

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Off Topic / Waco anniversary

« on: March 01, 2021, 01:59:30 AM »

Today we remember the four brave armed robbers who heroically gave their lives while breaking and entering into private property

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Modification Help / OBB vs OBB collisions using Separate Axis Theorem

« on: October 09, 2020, 12:26:17 PM »

I wrote some code to detect intersections between OBBs. I can think of a couple use cases for this, mainly that triggers in Blockland will always detect objects within it's AABB even if you have set up it's polyhedron attribute correctly, you could use this to get more accuracy. I'm fairly confident it works... though it may not be very intuitive or efficient. Maybe someone with experience in this area can roast my code or make it explode

You can also use this to detect OBB vs Segment/Point/Plane intersections by reducing relevant dimensions of the OBB to 0, but there are probably more efficient ways to do this

Green lines indicate that no overlap was detected when the OBBs were projected onto that axis. Red line indicates an overlap. In order for OBBs to be intersecting, there must be overlap on every axis.

Code: [Select]

$R_SAT_DebugLines = true;

function vectorClosestPoint(%vector, %startPoint, %point)
{
	%vN = vectorNormalize(%vector);
	%v2 = vectorSub(%point, %startPoint);
	%dot = vectorDot(%vN, vectorNormalize(%v2));
	
	%closestPoint = vectorAdd(%startPoint, vectorScale(%vN, %dot * vectorLen(%v2)));
	return %closestPoint;
}

function OBBIntersectVector(%center, %vector, %OBBPointsA, %OBBPointsB)
{
	%vector = vectorNormalize(%vector);

	%minAlongA = "";
	%maxAlongA = "";
	%minAlongB = "";
	%maxAlongB = "";
	
	for(%i = 0; %i < 8; %i++)
	{
		%a = %i * 3;
		
		%vertex = getWords(%OBBPointsA, %a, %a + 2);
		%projected = vectorClosestPoint( %vector, %center, %vertex );
		%OBBProjectedA = %OBBProjectedA @ %projected SPC "";
		
		%dot = vectorDot(%vertex, %vector);
		
		if(%minAlongA $= "" || %dot < %minAlongA)
			%minAlongA = %dot;
			
		if(%maxAlongA $= "" || %dot > %maxAlongA)
			%maxAlongA = %dot;
	}
	
	
	for(%i = 0; %i < 8; %i++)
	{
		%a = %i * 3;
		
		%vertex = getWords(%OBBPointsB, %a, %a + 2);
		%projected = vectorClosestPoint( %vector, %center, %vertex );
		%OBBProjectedB = %OBBProjectedB @ %projected SPC "";
		
		%dot = vectorDot(%vertex, %vector);
		
		if(%minAlongB $= "" || %dot < %minAlongB)
			%minAlongB = %dot;
			
		if(%maxAlongB $= "" || %dot > %maxAlongB)
			%maxAlongB = %dot;
	}	


	
	%overlapMax = getMax(%minAlongA, %minAlongB);
	%overlapMin = getMin(%maxAlongA, %maxAlongB);
	
	if($R_SAT_DebugLines)
	{
		if(%overlapMax <= %overlapMin)
		{
			drawLine(%center, vectorAdd(%center, %vector), "1 0 0 1", 0.05);
		}
		else
		{
			drawLine(%center, vectorAdd(%center, %vector), "0 1 0 1", 0.05);
		}
	}
	
	return %overlapMax <= %overlapMin;
}

$obbACenter = "5 5 5";
function OBBIntersectTest()
{
	%obbACenter = $obbACenter;
	
	%obbAForward = "1 1 1";
	%obbARight = vectorCross(%obbAForward, "0 0 1");
	%obbAUp = vectorCross(%obbARight, %obbAForward);
	
	%obbAF = 3;
	%obbAR = 5;
	%obbAU = 4;
	%obbAColor = "1 0 0 1";

	%obbBCenter = LocalClientConnection.player.getHackPosition();
	%obbBForward = LocalClientConnection.player.getForwardVector();
	%obbBRight = vectorCross(%obbBForward, "0 0 1");
	%obbBUp = vectorCross(%obbBRight, %obbBForward);
	%obbBF = 5 * 0.25;
	%obbBR = 5 * 0.25;
	%obbBU = 10.6 * 0.25;
	%obbBColor = "0 0 1 1";

	%pointsA = OBB(%obbACenter, %obbAForward, %obbARight, %obbAUp, %obbAF, %obbAR, %obbAU, %obbAColor);
	%pointsB = OBB(%obbBCenter, %obbBForward, %obbBRight, %obbBUp, %obbBF, %obbBR, %obbBU, %obbBColor);

	%intersectAU = OBBIntersectVector(%obbACenter, %obbAUp, %pointsA, %pointsB);
	%intersectAR = OBBIntersectVector(%obbACenter, %obbARight, %pointsA, %pointsB);
	%intersectAF = OBBIntersectVector(%obbACenter, %obbAForward, %pointsA, %pointsB);
	
	%intersectBU = OBBIntersectVector(%obbBCenter, %obbBUp, %pointsA, %pointsB);
	%intersectBR = OBBIntersectVector(%obbBCenter, %obbBRight, %pointsA, %pointsB);
	%intersectBF = OBBIntersectVector(%obbBCenter, %obbBForward, %pointsA, %pointsB);
	
	return 
	(
		%intersectAU && %intersectAF && %intersectAR && 
		%intersectBU && %intersectBF && %intersectBR
	);
}

function quadrilateralFromPolyhedron(%polyhedron, %corner, %center, %color)
{
	if(%color $= "") %color = getRandom() SPC getRandom() SPC getRandom() SPC 1;

	%forwardVector = getWords(%polyhedron, 3, 5);
	%rightVector = getWords(%polyhedron, 6, 8);
	%upVector = getWords(%polyhedron, 9, 11);

	%c0 = %corner;								// Backward Bottom Left
	%c1 = vectorAdd(%c0, %forwardVector);		// Forward Bottom Left
	%c2 = vectorAdd(%c0, %rightVector);			// Backward Bottom Right
	%c3 = vectorAdd(%c2, %forwardVector);		// Forward Bottom Right
	
	%c4 = vectorAdd(%c0, %upVector);			// Backward Top Left
	%c5 = vectorAdd(%c1, %upVector);			// Forward Top Left
	%c6 = vectorAdd(%c2, %upVector);			// Backward Top Right
	%c7 = vectorAdd(%c3, %upVector);			// Forward Top Right

	//for(%i = 0; %i < 8; %i++) drawLine(%c[%i], %c[%i], "1 0 0 1", 0.1);
	
	if($R_SAT_DebugLines)
	{
		// top rectangle
		drawLine(%c4, %c5, %color, 0.05);
		drawLine(%c6, %c7, %color, 0.05);
		drawLine(%c5, %c7, %color, 0.05);
		drawLine(%c4, %c6, %color, 0.05);
		
		// bottom rectangle
		drawLine(%c0, %c1, %color, 0.05);
		drawLine(%c2, %c3, %color, 0.05);
		drawLine(%c0, %c2, %color, 0.05);
		drawLine(%c1, %c3, %color, 0.05);
		
		// verticals
		drawLine(%c5, %c1, %color, 0.05);
		drawLine(%c7, %c3, %color, 0.05);
		drawLine(%c6, %c2, %color, 0.05);
		drawLine(%c0, %c4, %color, 0.05);
	}
	
	
	%obbPoints = %c0 SPC %c1 SPC %c2 SPC %c3 SPC %c4 SPC %c5 SPC %c6 SPC %c7;
	return %obbPoints;
}

function OBB_forward(%center, %forwardVector, %f, %r, %u, %color)
{
	%forwardVector = vectorNormalize(%forwardVector);
	%rightVector = vectorCross(%forwardVector, "0 0 1");
	%upVector = vectorCross(%rightVector, %forwardVector);
	return OBB(%center, %forwardVector, %rightVector, %upVector, %f, %r, %u, %color);
}

function OBB(%center, %forwardVector, %rightVector, %upVector, %f, %r, %u, %color)
{
	if(%color $= "") %color = getRandom() SPC getRandom() SPC getRandom() SPC 1;

	%forwardVector = vectorNormalize(%forwardVector);
	%rightVector = vectorNormalize(%rightVector);
	%upVector = vectorNormalize(%upVector);
	
	%hf = %f * 0.5;
	%hr = %r * 0.5;
	%hu = %u * 0.5;
		
	%corner = vectorAdd(%center, vectorScale(%forwardVector, -%hf));
	%corner = vectorAdd(%corner, vectorScale(%rightVector, -%hr));
	%corner = vectorAdd(%corner, vectorScale(%upVector, -%hu));
	
	return quadrilateralFromPolyhedron("0 0 0" SPC vectorScale(%forwardVector, %f) SPC vectorScale(%rightVector, %r) SPC vectorScale(%upVector, %u), %corner, %center, %color);
}

OBBIntersectTest() will create a rotated OBB near the origin, and a second OBB around the player's bounding box, and will return whether or not the OBBs intersected.

4

Modification Help / Navmesh / Pathfinding WIP

« on: August 01, 2020, 07:48:22 PM »

I'm working on navmesh again for Blockland. Thanks to the local torque wizards at BCC, I have made great strides since my last attempt and I can now actually link nodes together in a reasonable amount of time on meshes that have variable node sizes.

Will post updates in this thread. Or dump code if I abandon it. To be honest I'm really just trying to pressure the guys that have already made this and are keeping it to themselves into releasing it.

5

Modification Help / Anyone have experience with Ipquarx's BLMathLib?

« on: May 29, 2020, 09:19:34 PM »

Does this library work?
https://github.com/Ipdude/BLMathLib

If it does, can someone explain to me how to use some of the basic math operations? I can't get f_add(%num1, %num2) to return anything useful. Echoing it's result just gives me a global variable name, and that variable always contains 0.

6