Merge pull request #47 from jmiskovic/teleloco

Teleportation locomotion example

examples/Locomotion/Teleportation_Flat/main.lua

@@ -0,0 +1,118 @@
+-- right trigger: teleport-jump to targeted location
+-- right thumbstick: rotate the view horizontally
+
+local motion = {
+  pose = lovr.math.newMat4(), -- Transformation in VR initialized to origin (0,0,0) looking down -Z
+  thumbstickDeadzone = 0.4,   -- Smaller thumbstick displacements are ignored (too much noise)
+  -- Snap motion parameters
+  snapTurnAngle = 2 * math.pi / 12,
+  thumbstickCooldownTime = 0.3,
+  thumbstickCooldown = 0,
+  -- Teleport motion parameters
+  teleportDistance = 12,
+  blinkTime = 0.5,
+  blinkStopwatch = math.huge,
+  teleportValid = false,
+  targetPosition = lovr.math.newVec3(),
+  teleportCurve = lovr.math.newCurve(3),
+}
+
+function motion.teleport(dt)
+  -- Teleportation determining target position and executing jump when triggered
+  local handPose = mat4(motion.pose):mul(mat4(lovr.headset.getPose('right')))
+  local handPosition = vec3(handPose)
+  local handDirection = quat(handPose):direction()
+  -- Intersect with ground plane
+  local ratio =  vec3(handPose).y / handDirection.y
+  local intersectionDistance = math.sqrt(handPosition.y^2 + (handDirection.x * ratio)^2 + (handDirection.z * ratio)^2)
+  motion.targetPosition:set(handPose:translate(0, 0, -intersectionDistance))
+  -- Check if target position is a valid teleport target
+  motion.teleportValid = motion.targetPosition.y < handPosition.y and
+    (handPosition - motion.targetPosition):length() < motion.teleportDistance
+  -- Construct teleporter visualization curve 
+  local midPoint = vec3(handPosition):lerp(motion.targetPosition, 0.3)
+  if motion.teleportValid then
+    midPoint:add(vec3(0, 0.1 * intersectionDistance, 0)) -- Fake a parabola
+  end
+  motion.teleportCurve:setPoint(1, handPosition)
+  motion.teleportCurve:setPoint(2, midPoint)
+  motion.teleportCurve:setPoint(3, motion.targetPosition)
+  -- Start timer when jump is triggered, preform jump on half-blink
+  if lovr.headset.wasPressed('right', 'trigger') and motion.teleportValid then
+    motion.blinkStopwatch = -motion.blinkTime / 2
+  end
+  -- Preform jump with VR pose offset by relative distance between here and there
+  if motion.blinkStopwatch < 0 and
+     motion.blinkStopwatch + dt >= 0 then
+    local headsetXZ = vec3(lovr.headset.getPosition())
+    headsetXZ.y = 0
+    local newPosition = motion.targetPosition - headsetXZ
+    motion.pose:set(newPosition, vec3(1,1,1), quat(motion.pose)) -- ZAAPP
+  end
+  -- Snap horizontal turning (often combined with teleport mechanics)
+  if lovr.headset.isTracked('right') then
+    local x, y = lovr.headset.getAxis('right', 'thumbstick')
+    if math.abs(x) > motion.thumbstickDeadzone and motion.thumbstickCooldown < 0 then
+      local angle = -x / math.abs(x) * motion.snapTurnAngle
+      motion.pose:rotate(angle, 0, 1, 0)
+      motion.thumbstickCooldown = motion.thumbstickCooldownTime
+    end
+  end
+  motion.blinkStopwatch = motion.blinkStopwatch + dt
+  motion.thumbstickCooldown = motion.thumbstickCooldown - dt
+end
+
+function motion.drawTeleport()
+  -- Teleport target and curve
+  lovr.graphics.setColor(1, 1, 1, 0.1)
+  if motion.teleportValid then
+    lovr.graphics.setColor(1, 1, 0)
+    lovr.graphics.cylinder(motion.targetPosition, 0.05, math.pi/2,  1,0,0,  0.4, 0.4)
+    lovr.graphics.setColor(1, 1, 1)
+  end
+  lovr.graphics.setLineWidth(4)
+  lovr.graphics.line(motion.teleportCurve:render(30))
+  -- Teleport blink, modeled as gaussian function
+  local blinkAlpha = math.exp(-(motion.blinkStopwatch/ 0.25 / motion.blinkTime)^2)
+  lovr.graphics.setColor(0,0,0, blinkAlpha)
+  lovr.graphics.fill()
+end
+
+
+
+function lovr.update(dt)
+  motion.teleport(dt)
+end
+
+function lovr.draw()
+  lovr.graphics.setBackgroundColor(0.1, 0.1, 0.1)
+  lovr.graphics.transform(mat4(motion.pose):invert())
+  -- Render hands
+  lovr.graphics.setColor(1,1,1)
+  local radius = 0.04
+  for _, hand in ipairs(lovr.headset.getHands()) do
+    -- Whenever pose of hand or head is used, need to account for VR movement
+    local poseRW = mat4(lovr.headset.getPose(hand))
+    local poseVR = mat4(motion.pose):mul(poseRW)
+    poseVR:scale(radius)
+    lovr.graphics.sphere(poseVR)
+  end
+  -- Some scenery
+  lovr.math.setRandomSeed(0)
+  local goldenRatio = (math.sqrt(5) + 1) / 2
+  local goldenAngle = (2 - goldenRatio) * (2 * math.pi)
+  local k = 1.8
+  for i = 1, 500 do
+    local r = math.sqrt(i) * k
+    local x = math.cos(goldenAngle * i) * r
+    local y = math.sin(goldenAngle * i) * r
+    if lovr.math.random() < 0.05 then
+      lovr.graphics.setColor(0.8, 0.5, 0)
+    else
+      local shade = 0.1 + 0.3 * lovr.math.random()
+      lovr.graphics.setColor(shade, shade, shade)
+    end
+    lovr.graphics.cylinder(x, -0.01, y,  0.02, math.pi / 2, 1,0,0, 1, 1)
+  end
+  motion.drawTeleport()
+end