[Solved] Rendering a quad that always faces the camera

[Melonslise]

I'm trying to render a quad that always faces the player in the RenderWorldLastEvent. The code either fails to render completely or sometimes flickers in and out of view whenever the player moves. Can someone help?

Edited August 20, 2018 by Melonslise

[Cadiboo]

7 hours ago, Melonslise said:

I'm trying to render a quad that always faces the player in the RenderWorldLastEvent. The code either fails to render completely or sometimes flickers in and out of view whenever the player moves. Can someone help?

Look at render snowball

[Melonslise]

8 hours ago, Cadiboo said:

Look at render snowball

I tried adding and playing around with the code from RenderSnowball, but it gave really weird results. I also feel like the rotation code from RenderSnowball won't work with a long beam of sorts that I'm trying to make.

Here's my code:

 

 

public static void drawLine(double startX, double startY, double startZ, double endX, double endY, double endZ, int red, int green, int blue, int alpha, double width, float partialTick)
{
	Minecraft mc = Minecraft.getMinecraft();

	// TODO RenderPos from RenderManager
	double
	originX = mc.player.lastTickPosX + (mc.player.posX - mc.player.lastTickPosX) * (double) partialTick,
	originY = mc.player.lastTickPosY + (mc.player.posY - mc.player.lastTickPosY) * (double) partialTick,
	originZ = mc.player.lastTickPosZ + (mc.player.posZ - mc.player.lastTickPosZ) * (double) partialTick;

	Tessellator tessellator = Tessellator.getInstance();
	BufferBuilder buffer = tessellator.getBuffer();

	GlStateManager.pushMatrix();
	GlStateManager.disableCull();
	GlStateManager.disableTexture2D();

	GlStateManager.rotate(-mc.getRenderManager().playerViewY, 0F, 1F, 0F);
	GlStateManager.rotate(mc.getRenderManager().options.thirdPersonView == 2 ? -1F : 1F * mc.getRenderManager().playerViewX, 1F, 0F, 0F);
	GlStateManager.rotate(180F, 0F, 1F, 0F);

	buffer.begin(GL11.GL_QUADS, DefaultVertexFormats.POSITION_COLOR);
	buffer.pos(startX - originX, startY - originY - width / 2D, startZ - originZ).color(red, green, blue, alpha).endVertex();
	buffer.pos(endX - originX, endY - originY - width / 2D, endZ - originZ).color(red, green, blue, alpha).endVertex();
	buffer.pos(endX- originX, endY - originY + width / 2D, endZ - originZ).color(red, green, blue, alpha).endVertex();
	buffer.pos(startX - originX, startY - originY + width / 2D, startZ - originZ).color(red, green, blue, alpha).endVertex();
	tessellator.draw();

	GlStateManager.enableTexture2D();
	GlStateManager.enableCull();

	GlStateManager.popMatrix();
}

 

Edited August 20, 2018 by Melonslise

[Cadiboo]

What exactly are you trying to do?

[Melonslise]

6 minutes ago, Cadiboo said:

What exactly are you trying to do?

I'm trying to render beam with a start and end point that faces the player's look vector.

[Melonslise]

I got it!

Here's the code if anyone is interested:

 

public static void drawLine(Vec3d start, Vec3d end, int red, int green, int blue, int alpha, double width, float partialTick)
{
	Minecraft mc = Minecraft.getMinecraft();

	// TODO RenderPos from RenderManager?
	Vec3d origin = new Vec3d(mc.player.lastTickPosX + (mc.player.posX - mc.player.lastTickPosX) * (double) partialTick, mc.player.lastTickPosY + (mc.player.posY - mc.player.lastTickPosY) * (double) partialTick, mc.player.lastTickPosZ + (mc.player.posZ - mc.player.lastTickPosZ) * (double) partialTick);

	Vec3d camera = mc.player.getPositionEyes(partialTick);
	Vec3d direction = end.subtract(start).normalize();
	Vec3d startUp = direction.crossProduct(start.subtract(camera)).normalize().scale(width);
	Vec3d endUp = direction.crossProduct(end.subtract(camera)).normalize().scale(width);

	Tessellator tessellator = Tessellator.getInstance();
	BufferBuilder buffer = tessellator.getBuffer();

	GlStateManager.pushMatrix();
	GlStateManager.disableCull();
	GlStateManager.disableTexture2D();

	buffer.begin(GL11.GL_QUADS, DefaultVertexFormats.POSITION_COLOR);
	buffer.pos(start.x + startUp.x - origin.x, start.y + startUp.y - origin.y, start.z + startUp.z - origin.z).color(red, green, blue, alpha).endVertex();
	buffer.pos(start.x - startUp.x - origin.x, start.y - startUp.y - origin.y, start.z - startUp.z - origin.z).color(red, green, blue, alpha).endVertex();
	buffer.pos(end.x - endUp.x - origin.x, end.y - endUp.y - origin.y, end.z - endUp.z - origin.z).color(red, green, blue, alpha).endVertex();
	buffer.pos(end.x + endUp.x - origin.x, end.y + endUp.y - origin.y, end.z + endUp.z - origin.z).color(red, green, blue, alpha).endVertex();
	tessellator.draw();

	GlStateManager.enableTexture2D();
	GlStateManager.enableCull();

	GlStateManager.popMatrix();
}