3D Vector projection not working on Minecraft Forge...

[Player131]

Hello,

 

I'm trying to make a system like radar i made on GMod using 3D Vector projection. However it seams that Minecraft Forge refuses my formula.

 

I'm trying to transpose every entities 3D World coords into a 2D screen position, to be able to render red or green points in a box of 64x64 in the bottom right corner of the screen, here is my current code.

 

List<Entity> l = EntityFinder.findEntitiesInRayon(EntityType.LIVING, mc.thePlayer, 30, false); // This is a fuction i made using old classes of Minecraft 1.6, i reimplemented.
            drawString(mc.fontRenderer, "Entities arround you : " + l.size(), 5, 30, 0xE6FF00);

            ScaledResolution resolution = new ScaledResolution(mc, mc.displayWidth, mc.displayHeight);
            int j = resolution.getScaledWidth();
            int k = resolution.getScaledHeight();

            drawScreenAlphaColoredRect(j - 64, k - 64, 64, 64, new int[]{133, 133, 133, 16});//This function draws any rectangle you want at coords xy, with width and height. It supports alpha values too.
            for (Entity e : l){
                int[] xy = get2DFrom3D((float)e.posX, (float)e.posY, (float)e.posZ, resolution);
                int x = xy[0];
                int y = xy[1];
                drawScreenAlphaColoredRect(x, y, 2, 2, new int[]{255, 0, 0, 255});
            }

 

The get2DFrom3D void (it would more interesting if mc.entityRenderer.cameraZoom would be public) :

   public int[] get2DFrom3D(float x, float y, float z, ScaledResolution resolution) {
        int centerX = resolution.getScaledWidth() / 2;
        int centerY = resolution.getScaledHeight() / 2;
        Double d = ObfuscationReflectionHelper.getPrivateValue(EntityRenderer.class, FMLClientHandler.instance().getClient().entityRenderer, "cameraZoom");
        double zoom = d;
        int u = (int) (x / z * zoom + centerX);
        int v = (int) (y / z * zoom + centerY);

        return new int[]{u, v};
    }

 

[Player131]

I updated the code...

 

Now it's a little bit more good... Indead, i just used the code i was using on Garry's Mod Lua to make minimaps, but it seams that all coords systems are screwed up on Minecraft Forge...

 

The new function get2DFrom3D

    public int[] get2DFrom3D(float x, float y, float z, ScaledResolution resolution, EntityPlayer player) {
        int centerX = resolution.getScaledWidth() - 30;
        int centerY = resolution.getScaledHeight() - 30;

        Vec3 pos = Vec3.createVectorHelper(player.posX - x, player.posY - y, player.posZ - z);
        // / (mc.gameSettings.mouseSensitivity * 100)
        pos.rotateAroundY(-1 * (player.rotationYaw));
        int x1 = (int) (centerX + pos.yCoord / 5);
        int y1 = (int) (centerY + 0.6 * pos.xCoord);
        return new int[]{x1, y1};
    }

[TheGreyGhost]

Hi

 

The coordinate system that minecraft uses is shown on this page http://greyminecraftcoder.blogspot.co.at/2014/12/blocks-18.html

 

By 3D to 2D, do you mean you want an overhead view?  i.e. someone looking straight down from up high?

 

If so, your code looks about right except that your 64x64 rectangle should actually be a circle.  I would suggest you make sure to clip the result to a valid range (i.e. cull if it's outside the valid range) before drawing. 

 

Does it work how you expect or is there a problem?

 

-TGG

 

[Player131]

So i made two videos to show what the problem is. Note that the code i'm using in GMod Lua is based of the CAP one, so i give you the CAP code.

 

Here is what it should look like (don't care of textures or positions, they aren't corresponding to my mod) :

 

Here is what it renders on my Minecraft Mod. You can see that on my mod, sometimes you have position moving from up to down relative to yellow point (you), and sometimes it makes the contrary (witch is completely unexpected)

 

And at least the updated code on my mod :

    public float[] get2DFrom3D(float x, float y, float z, ScaledResolution resolution, EntityPlayer player) {
        int centerX = resolution.getScaledWidth() - 30;
        int centerY = resolution.getScaledHeight() - 30;

        Vec3 supperPos = Vec3.createVectorHelper(x, y, z);
        Vec3 playerPos = Vec3.createVectorHelper(player.posX, player.posY, player.posZ);
        Vec3 pos = playerPos.subtract(supperPos);
        // / (mc.gameSettings.mouseSensitivity * 100)
        float rotation = (float) ((double) ((player.rotationYaw * 4F) / 360F) + 0.5D);
        pos.rotateAroundY(-1 * (rotation));
        float x1 = (float) (centerX + pos.xCoord / 5);
        float y1 = (float) (centerY + 0.6 * pos.zCoord);
        return new float[]{x1, y1};
    }

 

And finaly the code that CAP uses (Pasted from their Github, and comented by me)

         for k, v in pairs(ents.GetAll()) do //Don't care it's a loop over every world entities
		if v:IsNPC() or v:IsPlayer() then //If this is a form of EntityLiving, don't care
			local ang = ply:GetAngles(); //There you go, interesting code starts here,
			local pos = ply:GetPos() - v:GetPos();
			pos:Rotate(Angle(0, -1*ang.Yaw, 0));
			local x1 = 256 + pos.y/5;
			local y1 = 512 + 0.3*pos.x; //And ends here
			if (math.abs(pos.z)<200) then
				surface.DrawTexturedRect(x1-16, y1-24, 32, 48);
			end
		end
	end

[TheGreyGhost]

I was having trouble from your video trying to figure out what was happening; maybe it would be better to test your code using a few "fake" fixed entity positions.

 

Are you sure your calculation of rotation is correct?  It looks like you are calculating a quadrant number, but rotateAroundY uses radians.

 

-TGG

[Player131]

I found what action seams to be breaking the function : Move Right and Move Left keys are breaking the function. Indead, sometimes, left/right keys will be forward/backward key for the minimap and sometimes this is completely correct... How can you explain that ?

[Player131]

Ok, i found the original cause of the left/right bug, it's because of the rotation everytime i rotate, x and z position aren't updated correctly with the player yaw rotation...

 

Here is my new code without rotation (working, but difficult to see where entities are coming from) :

    public float[] get2DFrom3D(float x, float y, float z, ScaledResolution resolution, EntityPlayer player) {
        int centerX = resolution.getScaledWidth() - 30;
        int centerY = resolution.getScaledHeight() - 30;

        Vec3 supperPos = Vec3.createVectorHelper(x, y, z);
        Vec3 playerPos = Vec3.createVectorHelper(player.posX, player.posY, player.posZ);
        Vec3 pos = playerPos.subtract(supperPos);
        //float rotation = (float) ((double) ((player.rotationYaw * 4F) / 360F) + 0.5D);
        //pos.rotateAroundY(-1 * (rotation));
        float x1 = (float) (centerX + pos.zCoord / 1);
        float y1 = (float) (centerY + 0.7 * pos.xCoord);
        return new float[]{x1, y1};
    }