求教大神,cocos3d效果,使用带法线的模型,美术有什么注意事项吗?

这个是案例的效果。

这个是我导出的模型效果,使用的同一套贴图。同一套代码。
这个是案例代码:
local sprite3d = cc.Sprite3D:create(“Sprite3DTest/sphere.c3b”)
sprite3d:setScale(2.0)
sprite3d:setPosition(cc.p(-30,0))
sprite3d:setRotation3D(cc.vec3(90.0, 0.0, 0.0))
sprite3d:setTexture(“Sprite3DTest/brickwork-texture.jpg”)
sprite3d:setCameraMask(2)
self:addChild(sprite3d)
local sprite3dBumped = cc.Sprite3D:create("Sprite3DTest/sphere_bumped.c3b")
sprite3dBumped:setScale(20.0)
sprite3dBumped:setPosition(cc.p(30,0))
sprite3dBumped:setRotation3D(cc.vec3(90.0, 0.0, 0.0))
sprite3dBumped:setCameraMask(2)
self:addChild(sprite3dBumped)
local radius = 100.0
local angle = 0.0
local reverseDir = false
local light = cc.PointLight:create(cc.vec3(0.0, 0.0, 0.0), cc.c3b(255, 255, 255), 1000.0)
local function lightUpdate()
light:setPosition3D(cc.vec3(radius * math.cos(angle), 0.0, radius * math.sin(angle)))
if reverseDir == true then
angle = angle - 0.01
if angle < 0.0 then
reverseDir = false
end
else
angle = angle + 0.01
if 3.14159 < angle then
reverseDir = true
end
end
end
local seq = cc.Sequence:create(cc.CallFunc:create(lightUpdate))
light:runAction(cc.RepeatForever:create(seq))
self:addChild(light)
local visibleSize = cc.Director:getInstance():getVisibleSize()
local camera = cc.Camera:createPerspective(60, visibleSize.width / visibleSize.height, 10, 1000)
camera:setPosition3D(cc.vec3(0.0, 0.0, 100.0))
camera:lookAt(cc.vec3(0.0, 0.0, 0.0))
camera:setCameraFlag(cc.CameraFlag.USER1)
self:addChild(camera)
请教各位大神了,这个要怎么弄?拜托了~!