Is there a way to detect whether I am moving towards a particular entity or if I am moving towards a particular entity type?
The issue I am having is to check whether I have hit a fence. At that point I want to turn around and move in the other direction. However, the collision is still happening so I can never auto move.
So I need to know if I am heading towards the fence or away from it.
I have tried this but unless I loop through all my fences I can't detect.
if (this.distanceTo(EntityRobotFence)< 50) this.stopMoving();
This doesn't work btw.
Have you tried using the following:
var target = ig.game.getEntitiesByType(EntityRobotFence); // or (EntityRobotFence)[0], etc
then:
if (this.distanceTo(target) < 50) this.stopMoving();
NOTE: this.distanceTo() returns the absolute distance in pixels from this entity's center to the other entity's center. So ensure your pixel distance is correct.
Related
I've been looking for awhile now for someone who had created a good example of making good physics in JavaFX, or even just a 'basic jumping mechanic' as the title says. I can't really find any information on it and I'm not really sure how to implement the idea.
All I want is a basic example, or just an explanation, or even just a point in the direction of what element of JFX I'm going to use.
Any help is appreciated.
Thanks
I'm assuming you already have some sort of game loop that ticks 60 times a second such as the AnimationTimer. If you want the jump height to be something like 200 pixels, you need to set and objects y-velocity (velocity is added to the objects location every tick) to a large negative number (as the object is moving upwards) and add a smaller amount every tick to this velocity until it hits zero, (this will be the top of the jump) and then keep adding this value to the y-velocity until it reaches the ground or collides with something. (This value will be your gravity constant)
In essence, you need to set the y-velocity to a high value then take away small increments every tick to slow the jump until the y-velocity hits 0, then begin adding the gravity constant again until the object hits the ground, hope this helps :)
I am working on a game which allows some buildings to be placed and
procedurally rotated.
I found the following rotation code which I am trying to incorporate:
function TransformModel(objects, center, new, recurse)
for _,object in pairs(objects) do
if object:IsA("BasePart") then
object.CFrame = new:toWorldSpace(center:toObjectSpace(object.CFrame))
end
if recurse then
TransformModel(object:GetChildren(), center, new, true)
end
end
end
which is invoked as follows in my building placement script:
local center = model:GetModelCFrame()
TransformModel( model:GetChildren(), center, center * CFrame.Angles(0,math.rad(45),0), true )
So the code works, somewhat... The model does sort of rotate but only after it jumps into the air and lands haphazardly before finally settling down in the rotated position, although its far from an exact 45 degree rotation after the physics effect of jumping in the air and settling back down.
I am not quite sure but I suspect there is a better way to accomplish this where the model smoothly rotates. Any help would be greatly appreciated.
Thanks,
Andy
GetModelCFrame is a deprecated method. It is instead recommended to utilize the PrimaryPart, GetPrimaryPartCFrame, and SetPrimaryPartCFrame. Setting the primary part designates a specific part in the model to serve as a base that you can move around via its CFrame. What's nice about this approach is that if you transform the PrimaryPart of a Model with these methods, all of the other parts in the Model will also transform to maintain their offset from the PrimaryPart.
For placing buildings and props, it is usually desired to have this part be a flat part at the bottom that represents the footprint of the building.
For example, consider the following model:
In this case the best part to make the primary part would be the one on the bottom. If your model doesn't have a part incorporated in the geometry then you can make an invisible and cancollide false part to serve as the base. In the following example, there is a tree model that doesn't have a wide base, but we want to make sure the footprint is large enough that it wouldn't overlap with other nearby objects:
In this case the yellow part should be made fully transparent at runtime.
So in terms of the code to actually orient a model in the way you want, all you have to do is call SetPrimaryPartCFrame with the new CFrame. The TransformModel function simply becomes:
local function TransformModel(model, newCFrame)
model:SetPrimaryPartCFrame(newCFrame)
end
When you want to call this function to say rotate a model 45 degrees:
local model = game.Workspace.Model
model.PrimaryPart = model.Base
local rotatedCFrame = model:GetPrimaryPartCFrame() * CFrame.Angles(0, math.rad(45), 0)
TransformModel(model, rotatedCFrame)
I believe I found an answer that works for my problem, though I am not sure if this is the best way to fix it. I created an extra part to act as a base which is the exact width and height of the model, the model then sits on top of the new base part and the base is anchored. That seems to have fixed it - is there a better way?
Now, GetPrimaryPartCFrame and SetPrimaryPartCFrame are not recommended for future projects. Instead, it is best to use SetPivot() and GetPivot().
(I understand that this topic was quite a while back ago, so I'm saying this to people who stumble upon this)
I am making a paper toss kind of game in Unity3d. I am implementing wind effect using constant force. I wanted to know how to make object fall in line with the target ie, if the object gets over the target, it should go in or fall in line with the target, not go behind or in front of the target. At present when I swipe applying a constant force, for different angles of swipe the distance moved by the object differs. Help would be much appreciated.
In FixedUpdate, use Physics.Raycast to check to see if the object is over the target. If so, set the x and z values of rigidbody.velocity to be zero (assuming y is the up/down axis in your game world) and disable the ConstantForce component (i.e. gameObject.GetComponent<ConstantForce>().enabled = false). Note that this won't be most realistic of movements, as it will seem like the object suddenly moves straight down when it goes over the target -- but it sounds like that's what you want.
I am tearing my hair out trying to figure out what seems to be a very easy problem. I know a lot of this stuff has been talked about tangentially, so apologies if this treads on well-covered ground, but I can't find anything specific to my solution (believe me, I've looked).
Basically I want to drag an object/sprite along a pre-defined, curved path (not just move it, but DRAG IT). Think of the iPhone's "Slide to unlock" thing, but instead of just dragging the slider left-to-right, make the path an arc or a wavy line.
My basic thinking was:
define a bezier path, set the object at the start point.
if the object is touched, check for hit detection on the bezier path in touchesMoved (or some similar function). if touches stay on the path, advance the sprite along the path until the path ends (in which case, task is finished) or the user's finger goes off the path (in which case, the object should go back to the beginning).
None of this is trivial (at least, that's how it seems). For example:
Doing hit detection on a Bezier path is a royal pain since you actually need to do it on the stroked portion, not the fill portion. And even then, I can't seem to find a way to do it on a path of any width -- only on the 1-point-wide path of the Bezier.
Moving an object partially along a path doesn't even seem possible: all of the animation methods move the sprite along the ENTIRE path. Also, doing this requires you to find the point on the path closest to the user's touch, which, if you've ever looked this up involves astoundingly complicated math.
I've thought of using rigid bodies to occupy all of the space EXCEPT the path, so the object can only move in the path. However, this requires the definition of curved rigid bodies some of which must be concave. Dead end.
Am I making this too hard? It doesn't seem that complicated. I don't need a whole solution, just a new way to think about this and kick in the right direction. Any help would be really appreciated.
How about this?
Consider the X Axis of your bezier
path.
Each time the user taps or interacts with the screen just look at the x portion of the touch
Map that X Coordinate with your path and move the object to the right position.
Yes, you are making this too hard.
Take the simplification suggested above (or along a circle, line, etc) if it works for, or if you really want to do it against a bézier curve, consider the following:
Look at the definition of the bézier curve
What you're looking for is to define a new object position P' from a current position P and a change in touch position D.
If you rephrase the original P(x,y) in terms of t (bézier curves are parametric), then the problem becomes finding how much t offset to add based on D.
Something involving the differential of the bezier fn at P might be a good way to do that. Ie, how much t would have been added had the curve just been a straight line coming from point P along the curve.
EDIT:
Transition between segments:
If each segment has t in [0,1), then you can detect t >= 1 and move on to the next segment, setting P to the end of the previous segment, and evaluating the movement again in relation to that point. There might have to be some heuristics involved if you have a lot of small points, etc.
Fairly simple question that Im sure you will laugh at me for.
I have two rectangles playerRect and wall.
I have an if statement with the condition being ..
if (CGRectIntersectsRect(playerRect,wall)) {
//handle collision here
}
The problem I'm having is working out which side actually hit the wall rectangle.
I need to know because then I stop te player from moving depending on which side hit.
Thanks for any help
Disco
I would add some direction property to my 'Player' object. This way when you detect a collision, you just check to see which way the player was moving prior to the collision and react accordingly.
Create a CGRect for each side of your object with just a width of 1 (or height of 1 depending on the side) and look for intersections with the sides instead of the entire object. If your object is moving faster than 1 pixel per collision check, then you would check the sides in addition to checking the entire object