Camera pick does not work on terrain?

[Sanctus]

Hey

I used this code code to place a entity at the mouse position on the terrain and it doesn't work.

 

Local p:TPick = CameraPick(camera, Vec3(mx, my, 1000), 0, TERRAIN_COL)
If(p <> Null)
PositionEntity(model, Vec3(p.x, p.y, p.z))
EndIf

 

The x and z coordinates are fine but the y (height) is totally wrong. The model stands in air on some places and then stays in the ground on other places.

Anyone experienced this before?

[Canardia]

I would use EntityPick, since it works fine with all objects. It allows you to make also more reusable code, since not always you have a camera, but always you have an entity.

[Masterxilo]

Did you set up:

Collisions(TERRAIN_COL,TERRAIN_COL);

?

[Sanctus]

EntityPick is useless. I need to pick with the mouse on the screen so I need more than a ray length.

Also if I didn't set up Collisions(TERRAIN_COL,TERRAIN_COL,1) it would work at all so yes I did it.

Way too much atention is put in that useless sandbox when a lot of very important parts of the engine don't work well or are undocumented.

I mean seriously what kind of professional game would use it?

[macklebee]

hmmm... i am not getting the results you are getting with objects floating in the air, but i am just doing a quick test in a standalone lua script...

require("Scripts/constants/collision_const")
require("Scripts/constants/engine_const")
require("Scripts/math/math")

RegisterAbstractPath("")        
Graphics(800,600)        
fw=CreateFramework()        
scene=LoadScene("Maps/train.sbx") 

controller=CreateController(1.8,0.45,0.25,45,0.9)
controller:SetCollisionType(COLLISION_CHARACTER,0)
controller:SetMass(100)
controller:SetPosition(Vec3(18,1,0))
camerapitch=fw.main.camera.rotation.x
camerayaw=fw.main.camera.rotation.y

local camera = fw.main.camera

HideMouse()
MoveMouse(GraphicsWidth()/2,GraphicsHeight()/2)

while KeyHit(KEY_ESCAPE)==0 do        
jump=KeyHit(KEY_SPACE)*6.0        
if controller:IsAirborne()==1 then jump=0 end        
gx=Round(GraphicsWidth()/2)        
gy=Round(GraphicsHeight()/2)        
dx=Curve((MouseX()-gx)/4.0,dx,3.0/AppSpeed())        
dy=Curve((MouseY()-gy)/4.0,dy,3.0/AppSpeed())        
MoveMouse(gx,gy)        
camerapitch=camerapitch+dy        
camerayaw=camerayaw-dx        
camerapitch=math.min(camerapitch,90)        
camerapitch=math.max(camerapitch,-89.99)       
fw.main.camera:SetRotationf(camerapitch,camerayaw,0,1)        
movespeed=4        
movesmoothing=10        
if controller:IsAirborne()==1 then                
	movesmoothing=200        
end 
 	move=Curve( (KeyDown(KEY_W)-KeyDown(KEY_S))*movespeed,move,movesmoothing)        
strafe=Curve( (KeyDown(KEY_D)-KeyDown(KEY_A))*movespeed,strafe,movesmoothing)        

if MouseHit(1)==1 then
	pick=CameraPick(camera,Vec3(GraphicsWidth()/2,GraphicsHeight()/2,1000.0),0,0)
	if pick~=nil then
		if pick.entity:GetClass()==ENTITY_TERRAIN then
			local oildrum = LoadModel("abstract::oildrum.gmf")
			oildrum:SetPosition(Vec3(pick.position.x, pick.position.y, pick.position.z))
		end
	end
end--

controller:Update(camerayaw,move,strafe,jump,400,1)  
fw:Update()        
fw.main.camera:SetPositionf(controller.position.x,controller.position.y+1.8,controller.position.z,1)        
fw:Render()

if pick~=nil then
	SetBlend(1)
	DrawText("Pick Position X: "..pick.position.x,0,60)
	DrawText("Pick Position Y: "..pick.position.y,0,80)
	DrawText("Pick Position Z: "..pick.position.z,0,100)
	SetBlend(0)
end
SetBlend(1)
DrawText("><", GraphicsWidth()/2-8,GraphicsHeight()/2-8)
SetBlend(0)

Flip(0)
end
controller:Free()

ShowMouse()

 

I am however seeing the strange values occurring for the Y value when done on flat terrain at 0 altitude, though seems to work just fine on higher elevation. Perhaps you can use the X & Z values from the pick for the command TerrainElevation to get a more precise Y value. Granted I have tried my method above with CreateCube and a physics model and even with strange Y values, it appears to place the model correctly.

[macklebee]

using the pick's X&Z for TerrainElevation appears to work just fine

require("Scripts/constants/collision_const")
require("Scripts/constants/engine_const")
require("Scripts/math/math")

RegisterAbstractPath("")        
Graphics(800,600)        
fw=CreateFramework()        
scene=LoadScene("Maps/train.sbx") 

controller=CreateController(1.8,0.45,0.25,45,0.9)
controller:SetCollisionType(COLLISION_CHARACTER,0)
controller:SetMass(100)
controller:SetPosition(Vec3(18,1,0))
camerapitch=fw.main.camera.rotation.x
camerayaw=fw.main.camera.rotation.y

local camera = fw.main.camera

HideMouse()
MoveMouse(GraphicsWidth()/2,GraphicsHeight()/2)

while KeyHit(KEY_ESCAPE)==0 do        
jump=KeyHit(KEY_SPACE)*6.0        
if controller:IsAirborne()==1 then jump=0 end        
gx=Round(GraphicsWidth()/2)        
gy=Round(GraphicsHeight()/2)        
dx=Curve((MouseX()-gx)/4.0,dx,3.0/AppSpeed())        
dy=Curve((MouseY()-gy)/4.0,dy,3.0/AppSpeed())        
MoveMouse(gx,gy)        
camerapitch=camerapitch+dy        
camerayaw=camerayaw-dx        
camerapitch=math.min(camerapitch,90)        
camerapitch=math.max(camerapitch,-89.99)       
fw.main.camera:SetRotationf(camerapitch,camerayaw,0,1)        
movespeed=4        
movesmoothing=10        
if controller:IsAirborne()==1 then                
	movesmoothing=200        
end 
 	move=Curve( (KeyDown(KEY_W)-KeyDown(KEY_S))*movespeed,move,movesmoothing)        
strafe=Curve( (KeyDown(KEY_D)-KeyDown(KEY_A))*movespeed,strafe,movesmoothing)        

if MouseHit(1)==1 then
	pick=CameraPick(camera,Vec3(GraphicsWidth()/2,GraphicsHeight()/2,1000.0),0,0)
	if pick~=nil then
		if pick.entity:GetClass()==ENTITY_TERRAIN then
			terrainheight=TerrainElevation(pick.entity, pick.position.x, pick.position.z)
			local oildrum = LoadModel("abstract::oildrum.gmf")
			oildrum:SetPosition(Vec3(pick.position.x, terrainheight, pick.position.z))
		end
	end
end--

controller:Update(camerayaw,move,strafe,jump,400,1)  
fw:Update()        
fw.main.camera:SetPositionf(controller.position.x,controller.position.y+1.8,controller.position.z,1)        
fw:Render()

SetBlend(1)
DrawText("Left-click mousebutton to pick terrain and set model",0,20)
DrawText("><", GraphicsWidth()/2-8,GraphicsHeight()/2-8)
if pick~=nil then
	DrawText("Pick Position X: "..pick.position.x,0,60)
	DrawText("Pick Position Y: "..terrainheight,0,80)
	DrawText("Pick Position Z: "..pick.position.z,0,100)
end
SetBlend(0)

Flip(0)
end
controller:Free()

ShowMouse()

[Sanctus]

Thanks for the answer. I will try it a bit later on.

Perhaps those "strange" values are very small values like 3.234234e-24 (don't remember the exact notation)

[macklebee]

yes, they are extremely small values - which is why I do not see any floating models...

[Sanctus]

Nope it does not work:

The only thing that get's me a good height is

PositionEntity(model, Vec3(p.x, TerrainElevation(terrain, p.z, p.x), p.z))

where p is the pick returned by CameraPick

But then x and y are a bit screwed up.

Look at tha picture attached. It's as if the x and z are from a flat terrain.

[macklebee]

It works fine for me in my example using TerrainElevation.

Instead of:

PositionEntity(model, Vec3(p.x, TerrainElevation(terrain, p.z, p.x), p.z))

try this:

PositionEntity(model, Vec3(p.x, TerrainElevation(terrain, p.x, p.z), p.z))

or

PositionEntity(model, Vec3(p.x, TerrainElevation(p.entity, p.x, p.z), p.z))

just depending on how you are filtering out just terrain picks... but either way it looks like you have your p.x & p.z swapped.

[Sanctus]

Yes I do have those swapped because otherwise it does not work at all.

I even had to make my rise/lower terrain functions that way because otherwise it doesn't work at all.

Look at this:

Method RiseTerrain(px:Float, py:Float, pz:Float, radius:Float, strength:Float)
For Local x:Int = px - radius / 2 To px + radius / 2
	For Local y:Int = pz - radius / 2 To pz + radius / 2
		Local d:Float = (radius / 2 - Dist2(px, pz, x, y))
		If d < 0
			d = 0
		EndIf
		Local h:Float = d / radius * strength / 1000.0
		If h < 0
			h = 0
		End If
		SetTerrainHeight(terrain, y + Width / 2, x + Height / 2, TerrainHeight(terrain, y + Width / 2, x + Height / 2) + h)
	Next
Next
UpdateTerrainNormals(terrain)
End Method

 

Notice this part "y + Width / 2, x + Height / 2, TerrainHeight(terrain, y + Width / 2, x + Height / 2) + h)". I just had to or it doesn't work right.

Geez there really has to be a tutorial about all the terrain features.

[macklebee]

well its hard to comment on your implementation in your own editor... I just know it works for the example I gave. If I swap the X & Z in my example, it doesn't work correctly. Perhaps Josh is rotating the terrain to make the terrain's X&Z planes line up with world's planes?