Regarding entity movement

[Undac]

Hello there, I have 2 questions and any help / idea is welcome.

 

1. How can I make sure that the camera does not go off terrain?

2. I need to move the camera forward (0Z) and sidewards (0X) along it's own axes, but without taking in consideration the rotation around 0Y axis (up/down). Any idea? I tried to make some pictures, hope they help:

 

 

and an example:

 

 

 

PS: I have solutions for both problems, but I am not satisfied with them.

1. "trap" the camera inside a cube

2. increment the camera position with sin(y rotation) on 0X, and with cos(y rotation) on 0Z

 

code below:

 

 

I actually have a MiscareCamera class that extends App, but I tried to move the relevant methods in the App class.

 

App.cpp

scroll to MiscareCamera()

don't forget to load a map!

 

 

#include "App.h"

 

//throws this exception if the entity is not inside the box

class exceptie{

const char* ce() const throw(){

return "Camera in afara formei!";

}

}Afara;

 

App::App() : window(NULL), context(NULL), world(NULL), camera(NULL) {}

 

App::~App() { delete world; delete window; }

 

bool App::Start(){

window = Leadwerks::Window::Create();

context = Leadwerks::Context::Create(window);

world = Leadwerks::World::Create();

camera = Leadwerks::Camera::Create();

 

//LOAD A MAP!!

if (!Leadwerks::Map::Load("/Maps/start.map")){

context->SetBlendMode(Leadwerks::Blend::Alpha);

context->DrawText("Failed to load a map! ", 2, 2);

context->Sync();

Sleep(1000);

}

 

camera->SetPosition(0, 30, 0);

return 1;

}

 

bool App::Loop(){

while (!(window->Closed() || window->KeyDown(Leadwerks::Key::Escape))){

App::MiscareCamera();

if (window->KeyDown(Leadwerks::Key:)){

Sleep(200);

while (!(window->KeyDown(Leadwerks::Key:))){

}

Sleep(200);

}

Leadwerks::Time::Update();

world->Update();

world->Render();

 

context->SetBlendMode(Leadwerks::Blend::Alpha);

context->DrawText("Rotatie: " + camera->GetRotation().ToString(), 2, 2);

context->DrawText("Pozitie: " + camera->GetPosition().ToString(), 2, 20);

context->Sync();

}

 

return 0;

}

 

void App::MiscareCamera(){

if (window->KeyDown(Leadwerks::Key::W)){

Leadwerks::Vec3 coordonate = camera->GetPosition();

try{

Leadwerks::Vec3 unghi = camera->GetRotation();

camera->SetPosition(coordonate.x + Leadwerks::Math::Sin(unghi.y), coordonate.y, coordonate.z + Leadwerks::Math::Cos(unghi.y));

inDreptunghi(camera->GetPosition());

}

catch (exceptie){

camera->SetPosition(coordonate.x, coordonate.y, coordonate.z);

}

}

 

if (window->KeyDown(Leadwerks::Key::S)){

Leadwerks::Vec3 coordonate = camera->GetPosition();

try{

Leadwerks::Vec3 unghi = camera->GetRotation();

camera->SetPosition(coordonate.x - Leadwerks::Math::Sin(unghi.y), coordonate.y, coordonate.z - Leadwerks::Math::Cos(unghi.y));

inDreptunghi(camera->GetPosition());

}

catch (exceptie){

camera->SetPosition(coordonate.x, coordonate.y, coordonate.z);

}

}

 

if (window->KeyDown(Leadwerks::Key:)){

try{

camera->Move(1, 0, 0);

inDreptunghi(camera->GetPosition());

}

catch (exceptie){

camera->Move(-1, 0, 0);

}

}

 

if (window->KeyDown(Leadwerks::Key::A)){

try{

camera->Move(-1, 0, 0);

inDreptunghi(camera->GetPosition());

}

catch (exceptie){

camera->Move(1, 0, 0);

}

}

 

if (window->KeyDown(Leadwerks::Key::R) && camera->GetPosition().y < 81){

camera->Move(0, 1, 0);

}

 

if (window->KeyDown(Leadwerks::Key::F) && camera->GetPosition().y > 34){

camera->Move(0, -1, 0);

}

 

if (window->KeyDown(Leadwerks::Key::E)){

Leadwerks::Vec3 unghi = camera->GetRotation();

camera->SetRotation(unghi.x, unghi.y + 2, 0);

}

 

if (window->KeyDown(Leadwerks::Key::Q)){

Leadwerks::Vec3 unghi = camera->GetRotation();

camera->SetRotation(unghi.x, unghi.y - 2, 0);

}

 

if (window->KeyDown(Leadwerks::Key::Z)){

Leadwerks::Vec3 unghi = camera->GetRotation();

if (unghi.x<30)

camera->SetRotation(unghi.x + 1, unghi.y, 0);

}

 

if (window->KeyDown(Leadwerks::Key::C)){

Leadwerks::Vec3 unghi = camera->GetRotation();

if (unghi.x>0)

camera->SetRotation(unghi.x - 1, unghi.y, 0);

}

}

 

void App::inDreptunghi(Leadwerks::Vec3 Obiect){

int xMin = -90, xMax = 90, zMin = -90, zMax = 90;

if (!(Obiect.x >= xMin && Obiect.x <= xMax))

throw Afara;

if (!(Obiect.z >= zMin && Obiect.z <= zMax))

throw Afara;

}

 

 

 

App.h

 

 

#pragma once

 

#include "Leadwerks.h"

 

#undef GetFileType

 

class App{

public:

Leadwerks::Window* window;

Leadwerks::Context* context;

Leadwerks::World* world;

 

App();

virtual ~App();

 

bool Start();

bool Loop();

 

private:

//mutate din MutareCamera.h

Leadwerks::Camera *camera;

void MiscareCamera();

void inDreptunghi(Leadwerks::Vec3 Obiect);

};

 

 

 

 

 

 

PPS: It didn't take the whitespaces when I copy-pasted from VS. Any idea how to solve this?

PSPS: I posted the camera movement method on pastebin: http://pastebin.com/BLBQgjAj

Edited February 2, 2016 by Undac

[AggrorJorn]

1. Simply check for camera world boundries. If you select the root of the scene you can see its size.

Pseudo code for the x axis

if (camera.pos.x < 0 )

camera.pos.x = 0

elseif (camera.pos.x > worldSize.x)

camera.pos.x = worldSize.x

[Undac]

Thanks for the response!

Regarding the first question, I want to check if the camera touches the terrain so it won't go under it.

[Brutile]

The first one is tricky, but the second can be done fairly easily. I don't have access to Leadwerks right now, so I can't code anything that works, but I can try to explain it.

1. Get your local forward movement direction, including the y axis

2. Set y to 0

3. Normalize your movement vector

4. Multiply the vector by your movement speed

5. Apply the movement

 

If you don't understand what I'm trying to explain, just let me know and I'll whip up the code in about 8 or so hours.

[lxFirebal69xl]

The first one is tricky, but the second can be done fairly easily. I don't have access to Leadwerks right now, so I can't code anything that works, but I can try to explain it.

1. Get your local forward movement direction, including the y axis

2. Set y to 0

3. Normalizeyour movement vector

4. Multiply the vector by your movement speed

5. Apply the movement

 

If you don't understand what I'm trying to explain, just let me know and I'll whip up the code in about 8 or so hours.

 

Just tried to do this myself but I keep messing up somewhere, could you show us an example of something simple?

[Undac]

Ok, I thought that there is a method similar to Entity::Move which allows us to ignore one of the rotations.

 

ixFirebal69xl - I cannot test right now, but I think that it's something like:

if (window->KeyDown(Leadwerks::Key::W)){

Leadwerks::Vec3 normalizedVector = camera->GetPosition();

normalizedVector.y = 0;

normalizedVector.Normalize(); // it sais that the function returns a Vec3, so it might be normalizedVector = normalizedVector.Normalize()

camera->Move(normalizedVector);

}

 

In case I understood it wrong and it does not work, you can use my solution meanwhile:

if (window->KeyDown(Leadwerks::Key::J)){

camera->SetPosition(camera->GetPosition().x + Leadwerks::Math::Sin(camera->GetRotation().y), camera->GetPosition().y, camera->GetPosition().z + Leadwerks::Math::Cos(camera->GetRotation().y));

}

[Brutile]

Just tried to do this myself but I keep messing up somewhere, could you show us an example of something simple?

 

I tried to code up an example, but in doing do, I decided to just write an entire RTS camera that should do what you want it to do.

You can get it here http://steamcommunity.com/sharedfiles/filedetails/?id=617085158

(It may not be available yet, as I only just submitted it)

 

Have a look at the script and see how to do it, or you may find that it does what you want it to do.

If it is missing something, just let me know (As long as it's not too complicated)