hallo may i have some assistance on this problem am struggling to solve on my own
the issue is that I used AABB to calculate the collision bounding boxes of nearby parts then switched to getpartboundsinbox but clearly the dragged part was never touching the sphere another issue is that whenever you hover the part below another part’s inlets the part(s) just completely disapear for some reason
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each bug occurs at the start of the two videos (incorrect sphere overlap and raycasted part resulting in transparency of all adjacent parts)
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Bump, still encountering the same issues
I thought aligned bounding boxes work for collisions, but this does not work when one is a sphere/cylinder and the other being a cube
Should I use GJK/Treys Algorithm
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Hi, can you reword the initial question with a bit more information? For one, you mostly said what didn’t work, instead of what you intended to happen. Also, if we could have some implementation details, like whether you are connecting the parts together via welds or just anchoring them to the position, that would be great.
From your video, I assume you want to place a part on the surface the mouse points to, while ensuring the location is free from overlap
Just to clear up some of the things you mentioned:
Is this relating to the point at 0:00-0:01 of the first video, when you jumped while dragging and the parts disappeared for a frame? If so, can you replicate it for a longer duration? If not, it might relate to this
I assume this is in the 1:10 video, but I must’ve missed it since I am not sure at what point you are referring to. Is the part hovering slightly over the sphere, overlapping the sphere, overlapping other parts touching the sphere? I don’t know what I am looking for
Though, to your point about GJK, I don’t think you should use it
- It wouldn’t be extendable since, to create the support functions, you need to store vertex positions. So you’d have to turn every mesh that you want blocks to be placed on into an EditableMesh (or I suppose manually storing the vertices in tables)
- It would be be slower than using roblox’s built-in spatial queries
Until I have a bit more info, I can’t really help. But do please reword the question, because I fear I misinterpret your aim
Also, is
real? I am not familiar with it
Your project looks really cool though!
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yes precisely
i figured, this only works on shapes that have convex hull decomposition
treys algorithm is another name for GJK thanks for responding to my post!
it seems you ahve more experience with CSG than me, but the issue is that whenever i hover the part below the sphere, the sphere somehow overlaps the part
thanks for replying to my post!
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Transparency issue
Would you be able to make a video showing the parts staying invisible when you highlight for a longer time than ~1 frame? lol. If not, check out the link I sent last time
Sphere issue
Are you talking about at this point in the video?
I don’t understand the unintended behavior from this. Unless your goal was to make a draggable part that never overlaps with what you are placing, finding the point of first impact of the part’s volume with the world’s geometry, instead of moving it to the raycast position. This diagram is an example of what I am talking about:
The “intended place direction” (or the raycast direction) is in red
The black outline is the world’s geometry
The orange is what I assume you are wanting, finding the point of first impact of the part and the sphere
The green is what is happening, where you move the draggable part to however far the raycast goes
If the orange is truly what you are wanting, you can do that with just a blockcast that has the dimensions of the part, the origin at the current camera position, and the direction of the raycast you are currently sending. Please let me know if I am understanding your intention and interpreting the issue correctly
I didn’t know that, thats interesting!
TLDR: Replicate the issue of transparency for a longer duration, and tell me the result. Tell me if my assumption/solution to the Sphere Issue is what you are wanting
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sorry i took a long time to answer back needed a break from roblox scripting in the mean time, still couldnt find any solutions in the past 3 weeks so i decided to bump again
also happy new year
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the videos i sent showed the issues that i encounter very briefly
this was what i meant:
i knew what the issues are i just dont know any way how to fix these nor do i know whether this is an engine bug or not
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the second issue is raycasting anything below the part itself which results in making both the part and the first thing you raycasted prior to disappear (the part inlets i think)
before raycasting
after raycasting
(the cursor does not show when taking screenshots but i pointed my cursor towards the palm of my characters hand in the after photo)
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bump nearly two months and ive had this issue for some time now
im not that skilled when it comes to the roblox spatial query api nor AABB (i have done extensive research for about 20+ hours now)
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yes yarik ik youre reading this post right now arent you
also am encountering another issue with pivoting the center of a model for some reason help pls
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