Block bot line of sight with smoke

[sunzenshen]

Description

Minimum viable bot detection for smoke.

Toolchain

• Windows MSVC VS2022

Linked Issues

• related Bot thermoptic and combat behaviors #1224

[AdamTadeusz]

untitled.mp4

Something's wrong

[DESTROYGIRL]

Wonder if this will make jeff blind in smoke since CNEO_NPCTargetSystem tests for MASK_BLOCKLOS?

[sunzenshen]

Diagnosed the issue as hitbox tracelines colliding with the LOS Blocker entity, which prevented damage.

Added a ShouldCollide that filters UTIL_TraceLines with CONTENTS_HITBOX, that skips the LOS Blocker and evaluates as normal.

bot_smoke_hitbox_fix_1.mp4

bot_smoke_hitbox_fix_2.mp4

[sunzenshen]

Wonder if this will make jeff blind in smoke since CNEO_NPCTargetSystem tests for MASK_BLOCKLOS?

Not with the current commits right now after some more testing, but I could take a look if that's something players are interested in.

[sunzenshen]

With the current approach, you'll need to add NPC and CONTENTS_DEBRIS masks to your NPC Tank code. Let me know how we feel about this approach in general.

bot_smoke_detection_jeff_2.mp4

[AdamTadeusz]

I'm not too fond of adding CONTENTS_DEBRIS to neo_npc_targetsystem and nextbotvisioninterface. I would personally revert the changes to those files, and do this in neo_smokelineofsightblocker.h instead

#ifndef NEO_SMOKELOSBLOCKER_NEO_H
#define NEO_SMOKELOSBLOCKER_NEO_H
#ifdef _WIN32
#pragma once
#endif

#include "cbase.h"

#define SMOKELINEOFSIGHTBLOCKER_ENTITYNAME	"env_smokelineofsightblocker"


class CNEOSmokeLineOfSightBlocker : public CBaseEntity {
public:
	DECLARE_CLASS(CNEOSmokeLineOfSightBlocker, CBaseEntity);
	DECLARE_DATADESC();

	void Spawn() override {
		BaseClass::Spawn();
		SetSolid(SOLID_BBOX);
		SetCollisionBounds(m_mins, m_maxs);
		SetSolidFlags(FSOLID_CUSTOMRAYTEST | FSOLID_CUSTOMBOXTEST);
	}

	static bool m_bNextEntitySeesThroughSmoke;
	bool TestCollision(const Ray_t& ray, unsigned int fContentsMask, trace_t& tr) override
	{
		if (fContentsMask & CONTENTS_BLOCKLOS)
		{
			if (m_bNextEntitySeesThroughSmoke)
			{
				return false;
			}

			tr.fraction = 0.f; // NEO NOTE (Adam) Shouldn't returning true be enough? Should we calculate correct value for the fraction?
			return true;
		}
		return false;
	}

	bool TestHitboxes(const Ray_t& ray, unsigned int fContentsMask, trace_t& tr) override
	{ // NEO NOTE (Adam) Shotguns used to use hulls for half of their pellets, not sure if this los blocker would have affected that, check if/when any weapons do again
		return false;
	}

	void SetBounds(const Vector& mins, const Vector& maxs) { m_mins = mins; m_maxs = maxs; }

private:
	Vector m_mins, m_maxs;
};

bool CNEOSmokeLineOfSightBlocker::m_bNextEntitySeesThroughSmoke = false;

#endif // NEO_SMOKELOSBLOCKER_NEO_H

Not sure if this is the correct way to do it, but it seems to me to be at least slightly better than what you have now

[sunzenshen]

I would personally revert the changes to those files, and do this in neo_smokelineofsightblocker.h instead

Those changes work well on my setup, though one thing to point out is that this also blocks the NPC tank vision on nt_rogue_ctg. As discussed on Discord, there's arguments for not blocking smoke LOS for that situation. Do we want to address that edge case in this PR or a different PR?

[sunzenshen]

  if (fContentsMask &= CONTENTS_BLOCKLOS)

The = is probably a typo, which was affecting collisions with physics objects. Tweaked this line to avoid overwriting fContentsMask.

smoke_phys_collision.mp4

[AdamTadeusz]

@sunzenshen I've updated the code snippet above to include a static bool m_bNextEntitySeesThroughSmoke. Assuming the vision checks are NOT done in parallel, this can then be set to true before the tracelines are done to ignore smokes. In the case of nextbots, I add the following to IsLineOfSightClearToEntity before the trace lines (and an import for neo_player.h and neo_smokelineofsightblocker.h)

#ifdef NEO
	auto neoPlayer = static_cast<CNEO_Player*>(GetBot()->GetEntity());
	CNEOSmokeLineOfSightBlocker::m_bNextEntitySeesThroughSmoke = neoPlayer ? neoPlayer->GetClass() == NEO_CLASS_SUPPORT : false;
#endif // NEO

For jeff, before the loop through all clients in CNEO_NPCTargetSystem::Think (and also the import neo_smokelineofsightblocker.h)

	CNEOSmokeLineOfSightBlocker::m_bNextEntitySeesThroughSmoke = true;

As long as every entity that checks for smokes updates the value before the traceline, it shouldn't be necessary to update the value again after the traceline, but maybe you want to set it to false afterwards just in case anyway

[Rainyan]

@sunzenshen Is this ready for review?

[sunzenshen]

@sunzenshen Is this ready for review?

Yup, I'm ready for review.

[Rainyan]

LGTM