Sign in to follow this  
Desarrollo3D

DX11 World*View*Project in DX11 problem

Recommended Posts

Desarrollo3D    100
This is the starting shader code:

float4 Pos0 : POSITION0...

matrix WorldViewProjection=World*View*Projection;

output.Pos = mul( Pos0, World );
output.Pos = mul( output.Pos, View );
output.Pos = mul( output.Pos, Projection );

and it works.

But if i change my code to: ( it should be the same...)


matrix WorldViewProjection=World*View*Projection;
output.Pos = mul( Pos0, WorldViewProjection );

i can see nothing!!! How it's possible?

Thanks!!

Share this post


Link to post
Share on other sites
Radikalizm    4807
[quote name='Desarrollo3D' timestamp='1313246638' post='4848648']
This is the starting shader code:

float4 Pos0 : POSITION0...

matrix WorldViewProjection=World*View*Projection;

output.Pos = mul( Pos0, World );
output.Pos = mul( output.Pos, View );
output.Pos = mul( output.Pos, Projection );

and it works.

But if i change my code to: ( it should be the same...)


matrix WorldViewProjection=World*View*Projection;
output.Pos = mul( Pos0, WorldViewProjection );

i can see nothing!!! How it's possible?

Thanks!!
[/quote]

No, those are not the same
I don't see why you want to change your original approach since it's just fine as it is

If you really insist on calculating your wvp-matrix in a single line you should use this:
[code]matrix WorldViewProjection = mul(mul(World, View), Projection);[/code]

Share this post


Link to post
Share on other sites
Desarrollo3D    100
Great!!! I thought that World*View*Projection resolved this way:

World * View then result * Projection;

Another Question why do you say that i should not change the original code?


Thanks a lot!!

Share this post


Link to post
Share on other sites
Radikalizm    4807
Because this:

[code]output.Pos = mul( Pos0, World );
output.Pos = mul( output.Pos, View );
output.Pos = mul( output.Pos, Projection );[/code]


is exactly the same as this:

[code]matrix WorldViewProjection=mul(mul(World,View),Projection)
output.Pos = mul( Pos0, WorldViewProjection );[/code]

The first option is more flexible for if you would need to do calculations with your view-space position for example

Share this post


Link to post
Share on other sites
MJP    19787
[quote name='mind in a box' timestamp='1313330228' post='4848958']
[quote]The * operator does not perform matrix multiplication, it performs per-component multiplication. [/quote]

Pity, in C++, the * operator does exactly this.
[/quote]

That depends on which math library you're using....

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • Similar Content

    • By RubenRS
      How do i open an image to use it as Texture2D information without D3DX11CreateShaderResourceViewFromFile? And how it works for different formats like (JPG, PNG, BMP, DDS,  etc.)?
      I have an (512 x 512) image with font letters, also i have the position and texcoord of every letter. The main idea is that i want to obtain the image pixel info, use the position and texcoords to create a new texture with one letter and render it. Or am I wrong in something?
    • By thmfrnk
      Hey,
      I found a very interesting blog post here: https://bartwronski.com/2017/04/13/cull-that-cone/
      However, I didn't really got how to use his "TestConeVsSphere" test in 3D (last piece of code on his post). I have the frustumCorners of a 2D Tile cell in ViewSpace and my 3D Cone Origin and Direction, so where to place the "testSphere"? I thought about to also move the Cone into viewspace and put the sphere to the Center of the Cell with the radius of half-cellsize, however what about depth? A sphere does not have inf depth?
      I am missing anything? Any Ideas?
      Thx, Thomas
    • By Modymek
      hi all
      I want to enable and disable shader in MPCH Media player Classic
      the MPCH have shader option using HLSL shaders
      I want the shader to read each file extension before it plays the file
      so if the video file name is video.GR.Mp4 it will play it in Grayscale shader 
      if it is not and standard file name Video.Mp4 without GR. unique extension so it plays standard without shader or end the shader
      here is the shader I have for grayscale
      // $MinimumShaderProfile: ps_2_0
      sampler s0 : register(s0);
      float4 main(float2 tex : TEXCOORD0) : COLOR {
          float c0 = dot(tex2D(s0, tex), float4(0.299, 0.587, 0.114, 0));
          return c0;
      }
       
      I want to add if or block stantement or bloean to detect file name before it call the shader in order to go to the procedure or disable it or goto end direct without it
       
      any thoughts or help
    • By noodleBowl
      I've gotten to part in my DirectX 11 project where I need to pass the MVP matrices to my vertex shader. And I'm a little lost when it comes to the use of the constant buffer with the vertex shader
      I understand I need to set up the constant buffer just like any other buffer:
      1. Create a buffer description with the D3D11_BIND_CONSTANT_BUFFER flag 2. Map my matrix data into the constant buffer 3. Use VSSetConstantBuffers to actually use the buffer But I get lost at the VertexShader part, how does my vertex shader know to use this constant buffer when we get to the shader side of things
      In the example I'm following I see they have this as their vertex shader, but I don't understand how the shader knows to use the MatrixBuffer cbuffer. They just use the members directly. What if there was multiple cbuffer declarations like the Microsoft documentation says you could have?
      //Inside vertex shader cbuffer MatrixBuffer { matrix worldMatrix; matrix viewMatrix; matrix projectionMatrix; }; struct VertexInputType { float4 position : POSITION; float4 color : COLOR; }; struct PixelInputType { float4 position : SV_POSITION; float4 color : COLOR; }; PixelInputType ColorVertexShader(VertexInputType input) { PixelInputType output; // Change the position vector to be 4 units for proper matrix calculations. input.position.w = 1.0f; // Calculate the position of the vertex against the world, view, and projection matrices. output.position = mul(input.position, worldMatrix); output.position = mul(output.position, viewMatrix); output.position = mul(output.position, projectionMatrix); // Store the input color for the pixel shader to use. output.color = input.color; return output; }  
    • By gomidas
      I am trying to add normal map to my project I have an example of a cube: 
      I have normal in my shader I think. Then I set shader resource view for texture (NOT BUMP)
                  device.ImmediateContext.PixelShader.SetShaderResource(0, textureView);             device.ImmediateContext.Draw(VerticesCount,0); What should I do to set my normal map or how it is done in dx11 generally example c++?
  • Popular Now