OMEGANAUT

[Ats]

try switching to ES2/GL3 then saving the file as ShaderDemoES2 and then reloading it. Maybe it's using cached shader objects or something.

I did that and it's still the same. Switching to ES2/GL3 seems to be not simple and with random results... I'm not sure if I want to do that.

(but I'll do it anyway )

[Kjell]

Hi Ats,

I did that and it's still the same. Switching to ES2/GL3 seems to be not simple and with random results... I'm not sure if I want to do that.

Sorry, my mistake. When you switch to ES2/GL3 on PC you can still use "legacy" features ( such as gl_Vertex ) due to backwards compatibility* There's no easy way to force ZGE to use OpenGL 3.3 ( the first version that isn't backwards-compatible ) without changing a bunch of stuff in the source code.

* ES 2.0 isn't backwards compatible with ES 1.1 though. But ES 1.1 doesn't support shaders ( and ES 2.0 doesn't support legacy shaders ) so you can't test it on Android either.

K

[Kjell]

Just to clear this up:

Code: Select all

┌─────────────┬──────────────┬───────────┬───────────────────┬────────────────┐
│             │PC(Compatible)│PC(ES2/GL3)│Android(Compatible)│Android(ES2/GL3)│
├─────────────┼──────────────┼───────────┼───────────────────┼────────────────┤
│Legacy Shader│OK            │OK         │ERROR              │ERROR           │
├─────────────┼──────────────┼───────────┼───────────────────┼────────────────┤
│Modern Shader│ERROR*        │OK         │ERROR              │OK              │
└─────────────┴──────────────┴───────────┴───────────────────┴────────────────┘

*Might not always produce compilation errors, but won't produce correct results.

K

[Ats]

Hi guys, it's been a long time.
I'm currently integrating my random planets in Omeganaut, and I have an interesting z order problem to show you.
Right now, I'm displaying the planet far away from the main camera with another fixed camera, so it doesn't move around with the player ship:

pic1.png (69.34 KiB) Viewed 14239 times

The problem is that the Material's ZBuffer of the planet gets in the way of the player ship, even if the planet coordinates are very far away from everything.

pic2.png (59.69 KiB) Viewed 14239 times

It works when I deactivate the ZBuffer of the planet and his ring:

pic3.png (57.83 KiB) Viewed 14239 times

But then again, I need the Zbuffer activated for the ring to display correctly on the planet...
What would be the correct way in order to solve this pesky problem?

[Ats]

I made a strip down example:

Code: Select all

<?xml version="1.0" encoding="iso-8859-1" ?>
<ZApplication Name="App" Caption="ZGameEditor application" Camera="CameraGame" FileVersion="2">
  <OnLoaded>
    <ZExpression>
      <Expression>
<![CDATA[App.Camera = CameraGame;

CameraPlanet.Position.X = 1000;
CameraPlanet.Position.Y = 0;
CameraPlanet.Position.Z = 0;]]>
      </Expression>
    </ZExpression>
    <SpawnModel Model="PlanetModel" Position="1000 0 -5"/>
    <SpawnModel Model="ShipModel" Position="0 -1 -8"/>
  </OnLoaded>
  <Content>
    <Model Name="PlanetModel" Rotation="0.05 0.05 0">
      <OnRender>
        <ZExpression Expression="App.Camera = CameraPlanet;"/>
        <UseMaterial Material="PlanetMaterial"/>
        <RenderMesh Mesh="SphereMesh"/>
        <UseMaterial Material="RingMaterial"/>
        <RenderMesh Mesh="RingMesh"/>
        <ZExpression Expression="App.Camera = CameraGame;"/>
      </OnRender>
    </Model>
    <Mesh Name="SphereMesh">
      <Producers>
        <MeshSphere ZSamples="32" RadialSamples="32"/>
      </Producers>
    </Mesh>
    <Material Name="PlanetMaterial">
      <Textures>
        <MaterialTexture Texture="PlanetBitmap"/>
      </Textures>
    </Material>
    <Bitmap Name="PlanetBitmap">
      <Producers>
        <BitmapCells PointsPlacement="2" RandomSeed="39" BorderPixels="0" PointCount="4"/>
      </Producers>
    </Bitmap>
    <Mesh Name="RingMesh">
      <Producers>
        <MeshSphere Scale="2 0.001 2" ZSamples="64" RadialSamples="4"/>
      </Producers>
    </Mesh>
    <Material Name="RingMaterial">
      <Textures>
        <MaterialTexture Texture="RingBitmap"/>
      </Textures>
    </Material>
    <Bitmap Name="RingBitmap">
      <Producers>
        <BitmapExpression>
          <Expression>
<![CDATA[//X,Y : current coordinate (0..1)
//Pixel : current color (rgb)
//Sample expression: Pixel.R=abs(sin(X*16));
Pixel.R = abs(sin(X*8));]]>
          </Expression>
        </BitmapExpression>
      </Producers>
    </Bitmap>
    <Camera Name="CameraGame"/>
    <Camera Name="CameraPlanet" Position="1000 0 0"/>
    <Mesh Name="ShipMesh">
      <Producers>
        <MeshBox Scale="0.2 0.2 3"/>
        <MeshBox Scale="1 0.2 0.2"/>
        <MeshTransform Position="0 0.1 -2"/>
        <MeshCombine/>
        <MeshBox Scale="2 0.2 0.2"/>
        <MeshTransform Position="0 -0.1 2"/>
        <MeshCombine/>
      </Producers>
    </Mesh>
    <Material Name="ShipMaterial">
      <Textures>
        <MaterialTexture Texture="ShipBitmap" TexCoords="1"/>
      </Textures>
    </Material>
    <Bitmap Name="ShipBitmap">
      <Producers>
        <BitmapNoise Octaves="2" Offset="0.73" Persistence="1" ZHeight="38.57" Color="2"/>
      </Producers>
    </Bitmap>
    <Model Name="ShipModel">
      <OnUpdate>
        <ZExpression>
          <Expression>
<![CDATA[time += App.DeltaTime;
CurrentModel.Position.X = cos(time);
CurrentModel.Position.Y = -1 + sin(time);
CurrentModel.Position.Z = -8 + cos(time * 0.1);]]>
          </Expression>
        </ZExpression>
      </OnUpdate>
      <OnRender>
        <UseMaterial Material="ShipMaterial"/>
        <RenderMesh Mesh="ShipMesh"/>
      </OnRender>
    </Model>
    <Variable Name="time"/>
  </Content>
</ZApplication>

I'm wondering if it would be simpler to display a huge planet at the limit of the main camera, instead of a small one filmed with the planet camera. This way, object shouldn't pass through it...

[Kjell]

Hi Ats,

This is actually very easy to solve .. the only thing you need to do is to clear the depth buffer after rendering your planet. Here's your example with one OpenGL call added to the last ZExpression in PlanetModel.OnRender

Code: Select all

<?xml version="1.0" encoding="iso-8859-1" ?>
<ZApplication Name="App" Caption="ZGameEditor application" Camera="CameraGame" FileVersion="2">
  <OnLoaded>
    <ZExternalLibrary ModuleName="opengl32">
      <Source>
<![CDATA[const int GL_DEPTH_BUFFER_BIT = 0x0100;

void glClear(int mode){}]]>
      </Source>
    </ZExternalLibrary>
    <ZExpression>
      <Expression>
<![CDATA[App.Camera = CameraGame;

CameraPlanet.Position.X = 1000;
CameraPlanet.Position.Y = 0;
CameraPlanet.Position.Z = 0;]]>
      </Expression>
    </ZExpression>
    <SpawnModel Model="PlanetModel" Position="1000 0 -5"/>
    <SpawnModel Model="ShipModel" Position="0 -1 -8"/>
  </OnLoaded>
  <Content>
    <Model Name="PlanetModel" Rotation="0.05 0.05 0">
      <OnRender>
        <ZExpression Expression="App.Camera = CameraPlanet;"/>
        <UseMaterial Material="PlanetMaterial"/>
        <RenderMesh Mesh="SphereMesh"/>
        <UseMaterial Material="RingMaterial"/>
        <RenderMesh Mesh="RingMesh"/>
        <ZExpression>
          <Expression>
<![CDATA[App.Camera = CameraGame;

// Clear the depth buffer!
glClear(GL_DEPTH_BUFFER_BIT);]]>
          </Expression>
        </ZExpression>
      </OnRender>
    </Model>
    <Mesh Name="SphereMesh">
      <Producers>
        <MeshSphere ZSamples="32" RadialSamples="32"/>
      </Producers>
    </Mesh>
    <Material Name="PlanetMaterial">
      <Textures>
        <MaterialTexture Texture="PlanetBitmap"/>
      </Textures>
    </Material>
    <Bitmap Name="PlanetBitmap">
      <Producers>
        <BitmapCells PointsPlacement="2" RandomSeed="39" BorderPixels="0" PointCount="4"/>
      </Producers>
    </Bitmap>
    <Mesh Name="RingMesh">
      <Producers>
        <MeshSphere Scale="2 0.001 2" ZSamples="64" RadialSamples="4"/>
      </Producers>
    </Mesh>
    <Material Name="RingMaterial">
      <Textures>
        <MaterialTexture Texture="RingBitmap"/>
      </Textures>
    </Material>
    <Bitmap Name="RingBitmap">
      <Producers>
        <BitmapExpression>
          <Expression>
<![CDATA[//X,Y : current coordinate (0..1)
//Pixel : current color (rgb)
//Sample expression: Pixel.R=abs(sin(X*16));
Pixel.R = abs(sin(X*8));]]>
          </Expression>
        </BitmapExpression>
      </Producers>
    </Bitmap>
    <Camera Name="CameraGame"/>
    <Camera Name="CameraPlanet" Position="1000 0 0"/>
    <Mesh Name="ShipMesh">
      <Producers>
        <MeshBox Scale="0.2 0.2 3"/>
        <MeshBox Scale="1 0.2 0.2"/>
        <MeshTransform Position="0 0.1 -2"/>
        <MeshCombine/>
        <MeshBox Scale="2 0.2 0.2"/>
        <MeshTransform Position="0 -0.1 2"/>
        <MeshCombine/>
      </Producers>
    </Mesh>
    <Material Name="ShipMaterial">
      <Textures>
        <MaterialTexture Texture="ShipBitmap" TexCoords="1"/>
      </Textures>
    </Material>
    <Bitmap Name="ShipBitmap">
      <Producers>
        <BitmapNoise Octaves="2" Offset="0.73" Persistence="1" ZHeight="38.57" Color="2"/>
      </Producers>
    </Bitmap>
    <Model Name="ShipModel">
      <OnUpdate>
        <ZExpression>
          <Expression>
<![CDATA[time += App.DeltaTime;
CurrentModel.Position.X = cos(time);
CurrentModel.Position.Y = -1 + sin(time);
CurrentModel.Position.Z = -8 + cos(time * 0.1);]]>
          </Expression>
        </ZExpression>
      </OnUpdate>
      <OnRender>
        <UseMaterial Material="ShipMaterial"/>
        <RenderMesh Mesh="ShipMesh"/>
      </OnRender>
    </Model>
    <Variable Name="time"/>
  </Content>
</ZApplication>

K

[Ats]

Thanks Kjell. An easy fix when you know about it. That was very helpful.
I'm going to rethink how I can handle the whole background with that new knowledge