Gamestudio Links
Zorro Links
Newest Posts
Where's the Wiki?
by Quad. 06/25/19 22:16
Published Gamestudio Games?
by Dooley. 06/25/19 16:59
Updating to A8 [SOLVED]
by Dooley. 06/25/19 16:00
Message from IB of open position
by Zheka. 06/25/19 13:58
FXCM: "Can't connect to price server"
by riinvest. 06/25/19 10:35
New Zorro version 2.12
by jcl. 06/25/19 09:42
Aum120 is ready
by Emre. 06/24/19 17:54
AUM Magazine
Latest Screens
The Space Between
Pogostuck: Rage With Your Friends
Worst Case Z
AckCon'18 - Lotter vs the World 2 - Preview Release
Who's Online Now
5 registered members (JeyKey II, wdlmaster, alibaba, jenGs, kvm), 574 guests, and 4 spiders.
Key: Admin, Global Mod, Mod
Newest Members
Theaisback, redye, rhe2564, Qw3rty, Dal
18239 Registered Users
Previous Thread
Next Thread
Print Thread
Rate Thread
How to recalculate normals after a shader moves vertices #474049
09/13/18 17:45
09/13/18 17:45
Joined: Apr 2002
Posts: 1,225
ny
jumpman Offline OP
Serious User
jumpman  Offline OP
Serious User

Joined: Apr 2002
Posts: 1,225
ny
Hello, how do I recalculate a model's normals after I move the vertices within the vertex shader? Is that possible?


A8 Pro 8.47
Re: How to recalculate normals after a shader moves vertices [Re: jumpman] #474195
09/28/18 09:03
09/28/18 09:03
Joined: Jun 2007
Posts: 1,229
Hiporope and its pain
txesmi Offline
Serious User
txesmi  Offline
Serious User

Joined: Jun 2007
Posts: 1,229
Hiporope and its pain
No, it is not possible. There is no way of accesing vertex buffers.

Salud!

Re: How to recalculate normals after a shader moves vertices [Re: txesmi] #474196
09/28/18 11:35
09/28/18 11:35
Joined: Sep 2003
Posts: 6,842
Kiel (Germany)
Superku Offline
Senior Expert
Superku  Offline
Senior Expert

Joined: Sep 2003
Posts: 6,842
Kiel (Germany)
I try to approximate correct normals manually after moving vertices in the vertex shader. For example when I rotate vertices I rotate the normal as well, or when the movement is sine based I add cosine values with the same argument. It's not exact but with the normalization in the pixel shader it oftentimes improves the result over leaving the normal unchanged.


"Falls das Resultat nicht einfach nur dermassen gut aussieht, sollten Sie nochmal von vorn anfangen..." - Manual

Check out my new game: Pogostuck: Rage With Your Friends
Re: How to recalculate normals after a shader moves vertices [Re: Superku] #474219
09/30/18 23:03
09/30/18 23:03
Joined: Apr 2002
Posts: 1,225
ny
jumpman Offline OP
Serious User
jumpman  Offline OP
Serious User

Joined: Apr 2002
Posts: 1,225
ny
How do you approximate normals after moving them in the XYZ directions?

(btw how are you rotating vertices?! laugh )

Here is a small version of what Im doing now:

Code:
-----VERTEX SHADER-----
InPos += mul(offset14,matWorldInv );  // move vertex

// Transform the vertex from object space to clip space: 
OutPos = mul(InPos, matWorldViewProj);  //  OutPos = mul(InPos, matWorldViewProj); 
  

// Transform the normal from object space to world space: 
  OutNormal = normalize(mul(InNormal, matWorld));


Last edited by jumpman; 09/30/18 23:08.

A8 Pro 8.47
Re: How to recalculate normals after a shader moves vertices [Re: jumpman] #474223
10/01/18 11:02
10/01/18 11:02
Joined: Sep 2003
Posts: 6,842
Kiel (Germany)
Superku Offline
Senior Expert
Superku  Offline
Senior Expert

Joined: Sep 2003
Posts: 6,842
Kiel (Germany)
Well in that shader code you quoted all vertices are moved by the same offset, no? Then the normal should stay the same. You'd have to show other code.
The approximation always depends on how you move the vertices, there's no general solution.

My rotation code usually looks something like this:
float effect = InPos.y/32.0; // depends on the model and type of "effect" you want to achieve, this would be for a vertical twist motion
float angle = sin(vecTime.w*0.1)*effect;
float sina = sin(angle);
float cosa = cos(angle);
float oldValue = InPos.x;
InPos.x = cosa*InPos.x - sina*InPos.z;
InPos.z = sina*oldValue + cosa*InPos.z;

If you want to rotate around any other position then the origin/ nullvector, subtract some shift vector or value first, do the rotation and then add the same amount again.


"Falls das Resultat nicht einfach nur dermassen gut aussieht, sollten Sie nochmal von vorn anfangen..." - Manual

Check out my new game: Pogostuck: Rage With Your Friends
Re: How to recalculate normals after a shader moves vertices [Re: Superku] #474264
10/02/18 16:21
10/02/18 16:21
Joined: Apr 2002
Posts: 1,225
ny
jumpman Offline OP
Serious User
jumpman  Offline OP
Serious User

Joined: Apr 2002
Posts: 1,225
ny
Hey superku, I forgot to add the vertex movement part based on texture. This uses tex2dlod, which is a texture fetch within the vertex shader. Wherever there is color information, these areas vertices will be moved:

Code:
////---- TOP LEFT -- CLOTH 0 RED
float4 cloth1 = tex2Dlod(clothSampler5, float4(InTex.x*0.5f,InTex.y*0.5f,0,0) ); 
float3 offset1 = float3(cloth1.r*vertMove0.r,cloth1.r*vertMove0.g,cloth1.r*vertMove0.b);

InPos += mul(offset1,matWorldInv );

// Transform the vertex from object space to clip space: 
OutPos = mul(InPos, matWorldViewProj);  //  OutPos = mul(InPos, matWorldViewProj); 
  

// Transform the normal from object space to world space: 
  OutNormal = normalize(mul(InNormal, matWorld));



As you can see, vertices are moved in the cardinal directions


A8 Pro 8.47

Moderated by  Blink, Hummel, Superku 

Gamestudio download | chip programmers | Zorro platform | shop | Data Protection Policy

oP group Germany GmbH | Birkenstr. 25-27 | 63549 Ronneburg / Germany | info (at) opgroup.de

Powered by UBB.threads™ PHP Forum Software 7.7.1