Get position of block on screen

[xleep]

Hi, I was trying to get the vertices of a block in screen space. Ideally, I would have some function that takes a blockPos, and returns the position of each of the eight corners of that block on the screen. After some searching I was able to find this and this, but I wasn't able to follow them. Would anybody be able to help?

[TheGreyGhost]

Hi

 

What's the reason you want those coordinates in screen space?  You might not need them, depending on what you want to do.

 

Otherwise, the approach taken in that code sample looks like the necessary approach but you will need to spend quite a bit of effort, trial and error to get it to work properly.  If you don't have a good understanding of 3D graphics, projections, viewports etc then it is going to be a very steep learning curve.  Unfortunately I don't have anything more suitable/specific to help.

 

-TGG

 

[Draco18s]

Yeah, converting from 3D space to Screen Space is annoying as hell.

I did the reverse in Unity a while back, but there's a bunch of Unity specific helper methods and objects involved.

 

Basically it involves doing all of the camera transform matrix math yourself. And that math is Not Fun.

[xleep]

Hey, sorry for the late replies.

 

Ideally, I would want to draw the outline of a block (like what it looks like when you hover over it in game), except all the lines would appear in front of the block (and they would be more noticable, ect. The end goal is to make it easy for the player to select a block). This is a really quickly done mockup of what I'd kind of want it to look like when the player looks at a block. There is probably another way to do this.

 

I'll try to follow draco18s's reply and see if I can get that working. Thanks!

[Beethoven92]

I think you may find this open source mod pretty useful to look into: https://www.curseforge.com/minecraft/mc-mods/ping

[xleep]

Oh that looks very helpful, I'll look into that. Thank you!

[Draco18s]

The block outline code that already exists might be useful.

You could also draw z-test-off quads in world space easily.

[TheGreyGhost]

You might also find this sample code useful (in 1.15.2; requires minor tweaks to 1.16.3)

https://github.com/TheGreyGhost/MinecraftByExample/blob/1-15-2-final/src/main/java/minecraftbyexample/usefultools/debugging/DebugBlockVoxelShapeHighlighter.java

It makes blocks outline like this

The lines behind blocks are hidden, but you can make them see through X-ray style by changing the render type

 

-TGG