• Advertisement

DX11 DirectX Intel HD and NVIDIA different behavior Geometry Shader

Recommended Posts

I try to draw lines with different thicknesses using the geometry shader approach from here:

https://forum.libcinder.org/topic/smooth-thick-lines-using-geometry-shader

It seems to work great on my development machine (some Intel HD). However, if I try it on my target (Nvidia NVS 300, yes it's old) I get different results. See the attached images. There

seem to be gaps in my sine signal that the NVS 300 device creates, the intel does what I want and expect in the other picture.

It's a shame, because I just can't figure out why. I expect it to be the same. I get no Error in the debug output, with enabled native debugging. I disabled culling with CullMode.None. Could it be some z-fighting? I have little clue about it but I tested to play around with the RasterizerStateDescription and DepthBias properties with no success, no change at all. Maybe I miss something there?

I develop the application with SharpDX btw.

Any clues or help is very welcome :)

 

sine_thick.png

frac_sine.png

Share this post


Link to post
Share on other sites
Advertisement

The GPU being that old, I would suspect you are running into either (a) A driver bug or (b) Some Geometry Shader resource limit for earlier implementations.

Share this post


Link to post
Share on other sites

I updated to the latest nvidia driver and still the same though. Resources I don't know. Maybe yes... I don't know how to check that though.

I couldn't figure it out till now. I found another more stable algorithm that is even simpler and produces variable line width without gaps on both devices. Although it is not so clever and uses more primitives in sum. The curves look even better actually. It is also a geometry shader that I tweaked a bit.

I suspected it maybe to be some kind of imprecision in the case here, but I am not sure why and at what point exactly.

If anyone else has a clue I might give it a try though to compare the performances with this new one I use.

Thank you though :-)

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


  • Advertisement
  • Advertisement
  • Popular Tags

  • Advertisement
  • Popular Now

  • Similar Content

    • By Karol Plewa
      Hi, 
       
      I am working on a project where I'm trying to use Forward Plus Rendering on point lights. I have a simple reflective scene with many point lights moving around it. I am using effects file (.fx) to keep my shaders in one place. I am having a problem with Compute Shader code. I cannot get it to work properly and calculate the tiles and lighting properly. 
       
      Is there anyone that is wishing to help me set up my compute shader?
      Thank you in advance for any replies and interest!
    • By turanszkij
      Hi, right now building my engine in visual studio involves a shader compiling step to build hlsl 5.0 shaders. I have a separate project which only includes shader sources and the compiler is the visual studio integrated fxc compiler. I like this method because on any PC that has visual studio installed, I can just download the solution from GitHub and everything just builds without additional dependencies and using the latest version of the compiler. I also like it because the shaders are included in the solution explorer and easy to browse, and double-click to open (opening files can be really a pain in the ass in visual studio run in admin mode). Also it's nice that VS displays the build output/errors in the output window.
      But now I have the HLSL 6 compiler and want to build hlsl 6 shaders as well (and as I understand I can also compile vulkan compatible shaders with it later). Any idea how to do this nicely? I want only a single project containing shader sources, like it is now, but build them for different targets. I guess adding different building projects would be the way to go that reference the shader source project? But how would they differentiate from shader type of the sources (eg. pixel shader, compute shader,etc.)? Now the shader building project contains for each shader the shader type, how can other building projects reference that?
      Anyone with some experience in this?
    • By osiris_dev
      Hello!
      Have a problem with reflection shader for D3D11:
      1>engine_render_d3d11_system.obj : error LNK2001: unresolved external symbol IID_ID3D11ShaderReflection
      I tried to add this:
      #include <D3D11Shader.h>
      #include <D3Dcompiler.h>
      #include <D3DCompiler.inl>
      #pragma comment(lib, "D3DCompiler.lib")
      //#pragma comment(lib, "D3DCompiler_47.lib")
      As MSDN tells me but still no fortune. I think lot of people did that already, what I missing?
      I also find this article http://mattfife.com/?p=470
      where recommend to use SDK headers and libs before Wind SDK, but I am not using DirectX SDK for this project at all, should I?
    • By trojanfoe
      Hi there, this is my first post in what looks to be a very interesting forum.
      I am using DirectXTK to put together my 2D game engine but would like to use the GPU depth buffer in order to avoid sorting back-to-front on the CPU and I think I also want to use GPU instancing, so can I do that with SpriteBatch or am I looking at implementing my own sprite rendering?
      Thanks in advance!
    • By Matt_Aufderheide
      I am trying to draw a screen-aligned quad with arbitrary sizes.
       
      currently I just send 4 vertices to the vertex shader like so:
      pDevCon->IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP);
      pDevCon->Draw(4, 0);
       
      then in the vertex shader I am doing this:
      float4 main(uint vI : SV_VERTEXID) : SV_POSITION
      {
       float2 texcoord = float2(vI & 1, vI >> 1);
      return float4((texcoord.x - 0.5f) * 2, -(texcoord.y - 0.5f) * 2, 0, 1);
      }
      that gets me a screen-sized quad...ok .. what's the correct way to get arbitrary sizes?...I have messed around with various numbers, but I think I don't quite get something in these relationships.
      one thing I tried is: 
       
      float4 quad = float4((texcoord.x - (xpos/screensizex)) * (width/screensizex), -(texcoord.y - (ypos/screensizey)) * (height/screensizey), 0, 1);
       
      .. where xpos and ypos is number of pixels from upper right corner..width and height is the desired size of the quad in pixels
      this gets me somewhat close, but not right.. a bit too small..so I'm missing something ..any ideas?
       
      .
  • Advertisement