Projecting Vector using dot product help

[MadPolygon]

Hi there,
So my brain is completely fried and I seemed to have forgotton basic vector math.

red is unreals trace.
yellow is my indication how far it should go.
Green is the target “line” the rays should extend to.

What I am trying to accomplish is basically my line trace projecting back to the orthogonal of the vector between the player and the object. It should shoot rays as far as the green plane. I am using the dot product and I am not sure where I am going wrong. If anyone has a solution it would be greatly appreciated!

[ClockworkOcean]

I would try putting everything on the click event for starters. At the moment, there’s no guarantee what you’re getting from tick is synchronized with the other stuff.

[MadPolygon]

tick is only a debug arrow i am drawing temporarily. The actual math happens without any tick.

[ClockworkOcean]

You’re right, sorry

[ullmatta]

Hey, I don’t get what you’re trying to do, but you could use a “line plane intersection” node, if you want to do what I think you do.

[rokenrock]

I’m not familiar with line plane intersection so I’m not sure if that’s what you want, but here’s how to do it using trig

Effectively all we do is divide distance by cos(theta), theta being the angle delta between the axis and player rotations. For Y we have to subtract 90.

Resulst:

[MadPolygon]

To clarify, here is what I am trying to do.

I want to shoot rays from cam and it should go into the direction until its perfectly orthogonal between the red vector and not past that.

like so. However may rays seem to be too short. I notice that the rays I fire are orthogonal to the target however what I want to ensure is that the rays going from p to fired ray and ray to cam are orthogonal, not the fired ray to the point p

currently, I get these results:

[Everynone]

It has so many applications that, once you know how it works, there’s no looking back. Some examples:

Left Mouse button pressed and released equivalent in enhanced input (or drag and drop)

Here’s some script allowing for picking up stuff and moving it in a specific plane only we determine ourselves manually: [image] The green debug plane visualises what’s going on. In short: shoot a beam (trace) from the screen centre towards the projected mouse cursor, when it eventually intersects that plane (which is infinitely large), place the actor at the intersect world coordinate. If I change the normal: [image] You could derive this Normal from the actor itself instead: [imag…

Line Trace from a 3d point to mouse location

You’re tracing with a fixed distance of 500, replacing the projection’s X with a fixed value. It’s actually hard to imagine how that would look like, a strangely distorted / twisted undulating surface mayhaps? , for sure. I want this trace to stay on the same plane as my character, so the X value of the start point & end point should be the same. Consider the following: [image] create a virtual plane where the character is and point it towards X (Plane Normal 1,0,0) …

[MadPolygon]

this looks like something that would solve this, ill check it out and let you know

[ullmatta]

These functions are built in allready.

(edit added blue lines)

[baobao4435]

here is another one.

[MadPolygon]

can you explainthis bit?

[baobao4435]

dot product + acosd is a fixed formula for getting the angle degrees to me ,I don’t know why it can do that though.I just know how to use it.

[MadPolygon]

this makes sense and is actually pretty simple, not why my intuition didnt grab that! Thank you!

[pezzott1]

The dot product of two unit vectors is the cosine of the angle. It doesn’t need to be turned into an angle then cos() again.

To get the length we can just do adjacent / dot product = hypothenuse.

[baobao4435]

@pezzott1

The dot product of two unit vectors is the cosine of the angle.

I didn’t know this before,well now I know .thanks