Terrain is not using tessellation

[klepto2]

With the latest Version, the terrainsystem doesn't use the  tessellation pipeline when you set something like this:

 camera->SetTessellation(12.0);

other geometry works fine.

[Josh]

Confirmed:

#include "UltraEngine.h"
#include "Components/CameraControls.hpp"

using namespace UltraEngine;

int main(int argc, const char* argv[])
{
    //Get the display list
    auto displays = GetDisplays();

    //Create a window
    auto window = CreateWindow("Ultra Engine", 0, 0, 1280, 720, displays[0], WINDOW_CENTER | WINDOW_TITLEBAR);

    //Create a world
    auto world = CreateWorld();
    world->SetAmbientLight(0);

    //Create a framebuffer
    auto framebuffer = CreateFramebuffer(window);

    //Create a camera
    auto camera = CreateCamera(world);
    camera->SetFov(70);
    camera->SetPosition(0, 50, 0);
    camera->SetRotation(45, 0, 0);
    camera->SetClearColor(0.125);
    camera->SetTessellation(4.0);
    //camera->SetDepthPrepass(false);
    //camera->SetWireframe(true);

    //Sunlight
    auto light = CreateDirectionalLight(world);
    light->SetRotation(45, 35, 0);
    light->SetColor(2);

    //Create terrain
    auto terrain = CreateTerrain(world, 512);
    terrain->LoadHeightmap("https://raw.githubusercontent.com/UltraEngine/Documentation/master/Assets/Terrain/512.r16", 100);

    //Create base material
    auto ground = CreateMaterial();
    auto diffusemap = LoadTexture("https://raw.githubusercontent.com/UltraEngine/Documentation/master/Assets/Materials/Ground/river_small_rocks_diff_4k.dds");
    auto normalmap = LoadTexture("https://raw.githubusercontent.com/UltraEngine/Documentation/master/Assets/Materials/Ground/river_small_rocks_nor_gl_4k.dds");
    ground->SetTexture(diffusemap, TEXTURE_DIFFUSE);
    ground->SetTexture(normalmap, TEXTURE_NORMAL);
    terrain->SetMaterial(ground);

    //Create paint material
    auto rocks = CreateMaterial();
    diffusemap = LoadTexture("https://raw.githubusercontent.com/UltraEngine/Documentation/master/Assets/Materials/Ground/Rocks_Dirt_Ground_2k.dds");
    normalmap = LoadTexture("https://raw.githubusercontent.com/UltraEngine/Documentation/master/Assets/Materials/Ground/Rocks_Dirt_Ground_2k_dot3.dds");
    auto dispmap = LoadTexture("https://raw.githubusercontent.com/UltraEngine/Documentation/master/Assets/Materials/Ground/Rocks_Dirt_Ground_2k_disp.dds");
    rocks->SetTexture(diffusemap, TEXTURE_DIFFUSE);
    rocks->SetTexture(normalmap, TEXTURE_NORMAL);
    rocks->SetTexture(dispmap, TEXTURE_DISPLACEMENT);
    rocks->SetDisplacement(4, -2);

    //Apply material based on terrain slope
    for (int x = 0; x < terrain->resolution.x; ++x)
    {
        for (int y = 0; y < terrain->resolution.y; ++y)
        {
            float slope = terrain->GetSlope(x, y);
            if (slope > 15.0f)
            {
                float wt = Min((slope - 15.0f) / 10.0f, 1.0f);
                terrain->SetMaterial(x, y, rocks, wt);
            }
        }
    }

    //Camera controls
    camera->AddComponent<CameraControls>();

    //Main loop
    while (window->Closed() == false and window->KeyDown(KEY_ESCAPE) == false)
    {
        world->Update();
        world->Render(framebuffer);
    }
    return 0;
}

 

[Josh]

Fixed!

I'm seeing a lot of stair-stepping on the example above. It looks like it is occurring at a higher frequency than the heightmap data itself...

[Josh]

The displacement map is using BC4 compression, so I would say displacement maps probably should not use any compression at all.

[klepto2]

Since the latest update (terrain-normals) it seems the terrainsystem is broken. 

this sample (https://www.ultraengine.com/learn/Terrain_SetMaterial?lang=cpp) shows no terrain at all.  (only when you comment out the LoadHeightmap the terrain shows up)

And in my code it shows with LoadHeightmap (using a png instead of r16) but still the terrain is flat.

 

[Josh]

If you do this it will work:

    //Create terrain
    auto terrain = CreateTerrain(world, 512);
    terrain->LoadHeightmap("https://raw.githubusercontent.com/UltraEngine/Documentation/master/Assets/Terrain/512.r16", 100);
    //terrain->SetScale(1, 100, 1);

However, I think I am going to change this behavior....

[klepto2]

Or to make it work as before, you can set  the default back to 1.0 instead of 1000.0.

With 1.0 it works as expected: 

 terrain->LoadHeightmap("https://raw.githubusercontent.com/UltraEngine/Documentation/master/Assets/Terrain/1024.r16",1);
    terrain->SetScale(1, 100, 1);

 

[klepto2]

Ok, with r16 maps it works now. Other image formats (png) still leads to flat terrain, even with provided scale parameter.

[Josh]

an 8-bit PNG is pretty useless. You will have severe stair-stepping artifacts.

I can add it in, but you won't want to use those.

[klepto2]

well, not in every case :

Source of the heightmap: https://johnflower.org/heightmap/mt-ruapehu-mt-ngauruhoe

and the code how i apply the height:

terrain->SetScale(tscale, scale, tscale);
    auto pixmap = LoadPixmap("Heightmaps/hm_nz.png");
    pixmap = pixmap->Resize(terrain->resolution.x, terrain->resolution.y);
    float low_p = 1.0;

    for (int x = 0; x < terrain->resolution.x; x++)
        for (int y = 0; y < terrain->resolution.y; y++)
        {
           auto h = pixmap->Sample(iVec2(x, y)).r;
           terrain->SetHeight(x, y,h);
           //auto h = terrain->GetHeight(x, y);
           if (h < low_p)
               low_p = h;
        }
   
    terrain->SetPosition(0.0, -1.0 * (low_p * scale), 0.0);

 

[klepto2]

btw, the mappingscale is not taken into account when texturing the terrain.

[Josh]

Looks like that is a high-precision PNG:

[klepto2]

thats why i said, not in every case  

In my opinion pixmap is pixmap, if a user wants to use other formats than r16, then why not. Just make a disclaimer, that low precision can lead to artifacts.