Rendering images in 3D, facing upwards

mih · 03-12-2010 06:55 PM

Hi, as in the title, i want to render image in 3d so it will be always facing up, something like decals but i want it to be in the air, is it possible ? or maybe it is possible to achive something similar using particles ?
thanks.

Panerox · 03-12-2010 07:43 PM

for example:

Code:

...

Image* image = ...;

Vtx3DSimple _A, _B, _C, _D;

_A.pos = Vec(-0.5, 0, -0.5);

_B.pos = Vec(0.5, 0, -0.5);

_C.pos = _Vec(0.5, 0, 0.5);

_D.pos = Vec(-0.5, 0, 0.5);    

_A.tex = Vec2(0,0);

_B.tex = Vec2(0,1);

_C.tex = Vec2(1,1);

_D.tex = Vec2(1,0);

...

switch (Renderer())

        {

        case RM_BLEND:

            {

            SetMatrix(<position + rotate + scale +...>);

            ALPHA_MODE alpha = D.alpha(ALPHA_BLEND_DEC);

            VI.image(image);

            VI.wrap();

            VI.face(_A, _B, _C, _D);

            VI.end();

            D.alpha(alpha);

            }

...

mih · 03-12-2010 08:03 PM

could you explain it little more ? You mean by using shaders or what ?

**Esenthel** · 03-12-2010 09:00 PM

you can also use simple mesh (made from 2 triangles)

Panerox · 03-12-2010 09:28 PM

(03-12-2010 08:03 PM)mih Wrote: could you explain it little more ? You mean by using shaders or what ?

no, not shaders.
i suggested to you that you can do this by using "VI - Vertex Index Buffer" (Vertex Index Buffer.h).
my example is even working smile

mih · 03-13-2010 08:24 AM

ok i'll give it a try, thanks smile

mih · 03-22-2010 07:21 PM

Finally I have found a time to try It, and I'm stuck pfft

Can someone direct me, what am I doing wrong ?
Here is how I was trying do to it :
As Panerox wrote these are the varibales :

Code:

Vtx3DSimple _A, _B, _C, _D;

Then in Init function I did that :

Code:

    _A.pos = Vec(-0.5, 0, -0.5);

    _B.pos = Vec(0.5, 0, -0.5);

    _C.pos = Vec(0.5, 0, 0.5);

    _D.pos = Vec(-0.5, 0, 0.5);   

    _A.tex = Vec2(0,0);

    _B.tex = Vec2(0,1);

    _C.tex = Vec2(1,1);

    _D.tex = Vec2(1,0);

    _A.nrm = Vec(0,1,0);

    _B.nrm = Vec(0,1,0);

    _C.nrm = Vec(0,1,0);

    _D.nrm = Vec(0,1,0);

and then In Draw function (I think I did something wrong here):

Code:

VI.image(Images("../data/logo+alpha.gfx"));

   VI.cull(true);

   VI.face(_A,_B,_C,_D);

   VI.end();

But the Image didn't show up, so any ideas wink

?

**Esenthel** · 03-22-2010 07:30 PM

try setting SetMatrix
try disabling culling for testing

mih · 03-22-2010 07:35 PM

Hm still nothing. That's how the whole code is looking like:

Code:

/******************************************************************************/

#include "stdafx.h"

/******************************************************************************/

Mesh mesh;

Vtx3DSimple _A, _B, _C, _D;

/******************************************************************************/

void InitPre()

{

   App.name("Rendering");

   App.flag=APP_MS_EXCLUSIVE;

   Paks.add("../data/engine.pak");

}

/******************************************************************************/

Bool Init()

{

   Cam.dist=2;

   mesh.create(1).base(0).create(Ball(1),VTX_TEX0|VTX_NRM|VTX_TNG);               // create Mesh with 1 MeshPart, and create this MeshPart's base from Ball with automatic texture coordinates, normals and tangents

   mesh.setMaterial(Materials("../data/mtrl/brick/0.mtrl")).setRender().setBox(); // set mesh material, rendering version and bounding box

    _A.pos = Vec(-0.5, 0, -0.5);

    _B.pos = Vec(0.5, 0, -0.5);

    _C.pos = Vec(0.5, 0, 0.5);

    _D.pos = Vec(-0.5, 0, 0.5);    

    _A.tex = Vec2(0,0);

    _B.tex = Vec2(0,1);

    _C.tex = Vec2(1,1);

    _D.tex = Vec2(1,0);

    _A.nrm = Vec(0,1,0);

    _B.nrm = Vec(0,1,0);

    _C.nrm = Vec(0,1,0);

    _D.nrm = Vec(0,1,0);

   return true;

}

/******************************************************************************/

void Shut()

{

}

/******************************************************************************/

Bool Update()

{

   if(Kb.bp(KB_ESC))return false;

   CamHandle(1.5,10,CAMH_ZOOM|CAMH_ROT);

   return true;

}

/******************************************************************************/

void Render() // Rendering Function

{

   switch(Renderer()) // Rendering Function will be called multiple times for different Rendering Modes

   {

      // the most important is the "prepare" mode in which you should draw all the meshes and add lights

      case RM_PREPARE:

      {

         // add directional light

         LightDir(Vec(0,0,1)).add();

      }break;

   }

}

void Draw()

{

   //D.clear(WHITE);

   Renderer(Render); // render with 'Render' function

   SetMatrix();

   VI.image(Images("../data/logo+alpha.gfx"));

   VI.face(_A,_B,_C,_D);

   VI.end();

   D.text(0,0.9,S+"Fps: "+Time.fps()); // show number of fps

}

/******************************************************************************/

Maybe ther's something else wrong with It ? (I just edited the first rendering tutorial)

**Esenthel** · 03-22-2010 07:57 PM

you should set colors of vertexes
_A.color=WHITE;...

mih · 03-22-2010 07:58 PM

Didn't know that It has to be used too, thanks It's working now wink

**Esenthel** · 03-22-2010 08:05 PM

if your codes they were set to transparent black (0) by default

Rendering images in 3D, facing upwards
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