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我想在Lua中实现GLM的项目和unproject函数,但结果是...值得怀疑。据我所知,我的代码(如下所示)与GLM几乎相同,但是如下面的视频所示,文本不会按预期显示。当我将相机带到0,0,0时,文字会形成菱形图案,这很有趣。mat4项目/ unproject不工作
这里应该显示的是cube.001到cube.009应该绘制在它们各自的立方体顶部,而不管相机在哪里移动。 cube.001是TL,cube.009是BR。
要全面了解我们的mat4库(和其他垃圾),请访问here。
-- https://github.com/g-truc/glm/blob/master/glm/gtc/matrix_transform.inl#L317
function mat4.project(obj, view, projection, viewport)
local position = { obj.x, obj.y, obj.z, 1 }
position = view * position
position = projection * position
position[1] = position[1]/position[4] * 0.5 + 0.5
position[2] = position[2]/position[4] * 0.5 + 0.5
position[3] = position[3]/position[4] * 0.5 + 0.5
position[4] = position[4]/position[4] * 0.5 + 0.5
position[1] = position[1] * viewport[3] + viewport[1]
position[2] = position[2] * viewport[4] + viewport[2]
return vec3(position[1], position[2], position[3])
end
-- https://github.com/g-truc/glm/blob/master/glm/gtc/matrix_transform.inl#L338
function mat4.unproject(win, view, projection, viewport)
local inverse = (projection * view):inverse()
local position = { win.x, win.y, win.z, 1 }
position.x = (position.x - viewport[1])/viewport[3]
position.y = (position.y - viewport[2])/viewport[4]
position[1] = position[1] * 2 - 1
position[2] = position[2] * 2 - 1
position[3] = position[3] * 2 - 1
position[4] = position[4] * 2 - 1
position = inverse * position
position[1] = position[1]/position[4]
position[2] = position[2]/position[4]
position[3] = position[3]/position[4]
position[4] = position[4]/position[4]
return vec3(position[1], position[2], position[3])
end
-- Get projection from cubes
local viewport = { 0, 0, 1280, 720 }
for _, cube in ipairs(self.cubes) do
local model = cpml.mat4()
:translate(cube.position)
:rotate(cube.orientation.x, { 1, 0, 0 })
:rotate(cube.orientation.y, { 0, 1, 0 })
:rotate(cube.orientation.z, { 0, 0, 1 })
:scale(cube.scale)
local projection = cpml.mat4.project(
cube.position,
self.camera.view:transpose(),
self.camera.projection:transpose(),
viewport
)
end
在unproject我看到position.x分配给两次,而不是它是第二次。 – 2014-10-29 00:59:23
谢谢你发现,我现在就去改变它。我们还没有实际测试过项目,因为项目导致我们有这么多问题。 :) – Karai17 2014-10-29 01:00:19