Simple Shader Question (8 posts)

  • Profile picture of t0neg0d t0neg0d135p said 3 months, 2 weeks ago:

    Am I completely off base here, or shouldn’t I be able to move a texture (basing this off of the Unshaded material/vert/frag) by updating texCoord1?

    If I slowly increase the x or y of the vec2 from 0 to 1, shouldn’t it move the texture?

    Reaaaaallly sorry for the stupid question.

    #
  • Profile picture of pspeed pspeed815p said 3 months, 2 weeks ago:

    Yes, it should. But if it isn’t then we haven’t been given enough information as to why it isn’t.

    #
  • Profile picture of t0neg0d t0neg0d135p said 3 months, 2 weeks ago:

    So, I updated the Unshaded.vert with the following (material def file allows for setting Offset)

    uniform mat4 g_WorldViewProjectionMatrix;
attribute vec3 inPosition;

#if defined(HAS_COLORMAP) || (defined(HAS_LIGHTMAP) && !defined(SEPARATE_TEXCOORD))
    #define NEED_TEXCOORD1
#endif

#ifdef NEED_TEXCOORD1
    attribute vec2 inTexCoord;
    varying vec2 texCoord1;
    varying vec2 Offset;
#endif

#ifdef SEPARATE_TEXCOORD
    attribute vec2 inTexCoord2;
    varying vec2 texCoord2;
#endif

#ifdef HAS_VERTEXCOLOR
    attribute vec4 inColor;
    varying vec4 vertColor;
#endif

void main(){
    #ifdef NEED_TEXCOORD1
        texCoord1 = vec2((inTexCoord[0]+Offset[0]),(inTexCoord[1]+Offset[1]));
    #endif

    #ifdef SEPARATE_TEXCOORD
        texCoord2 = inTexCoord2;
    #endif

    #ifdef HAS_VERTEXCOLOR
        vertColor = inColor;
    #endif

    gl_Position = g_WorldViewProjectionMatrix * vec4(inPosition, 1.0);
}

    So the loop updates Offset from value 0 to 1 in increments of .01f
    The texture moves… only when I rotate the camera along the Zaxis (looking up and down). I know it has something to do with the last line (gl_Position). I am assuming I need to swap out WorldView for something Local to the rendered object?

    Any help would be appreciated!

    #
  • Profile picture of pspeed pspeed815p said 3 months, 2 weeks ago:

    Offset is not a uniform it’s a varying… so it probably contains random garbage that changes as you look around.

    I’m surprised it compiled at all.

    Did you want it to be a uniform or a vertex attribute?

    Also note that you can just use g_Time if you set that up right in the j3md.

    #
  • Profile picture of t0neg0d t0neg0d135p said 3 months, 2 weeks ago:

    I see now. Let me try setting it to a uniform.

    #
  • Profile picture of pspeed pspeed815p said 3 months, 2 weeks ago:

    Also, if you have a uniform named “Offset” then it will be “m_Offset” in the shaders.

    #
  • Profile picture of t0neg0d t0neg0d135p said 3 months, 2 weeks ago:

    This worked like a charm!

    uniform mat4 g_WorldViewProjectionMatrix;
attribute vec3 inPosition;

#if defined(HAS_COLORMAP) || (defined(HAS_LIGHTMAP) && !defined(SEPARATE_TEXCOORD))
    #define NEED_TEXCOORD1
#endif

#ifdef NEED_TEXCOORD1
    attribute vec2 inTexCoord;
    varying vec2 texCoord1;
    uniform vec2 m_Offset;
#endif

#ifdef SEPARATE_TEXCOORD
    attribute vec2 inTexCoord2;
    varying vec2 texCoord2;
#endif

#ifdef HAS_VERTEXCOLOR
    attribute vec4 inColor;
    varying vec4 vertColor;
#endif

void main(){
    #ifdef NEED_TEXCOORD1
        texCoord1 = vec2((inTexCoord[0]+m_Offset[0]),(inTexCoord[1]+m_Offset[1]));
    #endif

    #ifdef SEPARATE_TEXCOORD
        texCoord2 = inTexCoord2;
    #endif

    #ifdef HAS_VERTEXCOLOR
        vertColor = inColor;
    #endif

    gl_Position = g_WorldViewProjectionMatrix * vec4(inPosition, 1.0);
}

    Now to figure out how to set up the g_Time in the material def file. Although, I would love to be able to vary the speed, so I am assuming I’ll need to define this as well.

    Thanks a ton for the help!

    #
  • Profile picture of pspeed pspeed815p said 3 months, 2 weeks ago:

    Yeah, but speed won’t need to be set as often as offset, probably.

    Under WorldParameters… put Time

    Then you will have access to g_Time in your shader.

    #