Terrain API - Missing methods and Refinement

[klepto2]

Hi, 

while i am working on my "Environement / Atmosphere / Weather" - system i'm working a lot with the terrain system and found some bugs and missing functionality from the API.

Bugs:

The layer system works only when you first assign a material to the terrain. In my opinion,  this should not be required and a default terrain material should be set until it is overridden by the user (later planetary implementation or streaming terrain).

On further investigation this was just a one time bug for me, but i let it here for reference.

#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);

    //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");
    terrain->SetScale(1, 100, 1);

    //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); // Comment out this line and the whole terrain will be black

    //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);

    int layer = terrain->AddLayer(rocks);
    terrain->SetLayerTextureMapping(layer, TERRAINMAPPING_VERTICAL);
    //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->SetLayerWeight(layer,x, y, 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;
}

Missing methods: 

1. The Fill method is commented out in the header file and my should maybe renamed to FillLayer(int layerid)

2. The methods to set and get the layer scaling are missing, or better: they are in the protected area.

3 All get Methods for LayerProperties should be provided. Currently it is not possible to access things like the Slope / height constraints of a specific layer.

Edited August 10, 2023 by klepto2
Addition

[klepto2]

Also Terrain::GetElevation doesn't take the Terrain-Position into account. Which is understandable as the terrain  matrix is fully modifiable (scale, position and rotation), but it should be mentioned in the Docs. 

[Josh]

When I comment out the base material, the correct behavior is displayed. The SetLayerWeight command by default normalizes the weights, so each tile receives 100% weighting, since there is no other material present:

Even if the normalize parameter is set to false (after the update coming later today) there will be no support for blending a material on top of the untextured terrain. There's an intermediate step that normalizes the weights again.

[Josh]

On 8/10/2023 at 12:54 AM, klepto2 said:

1. The Fill method is commented out in the header file and my should maybe renamed to FillLayer(int layerid)

2. The methods to set and get the layer scaling are missing, or better: they are in the protected area.

3 All get Methods for LayerProperties should be provided. Currently it is not possible to access things like the Slope / height constraints of a specific layer.

1. Added Fill() method as a convenience function.

2. Set/get layer scale are now public (in update later today)

3. These methods are now public.

I think that addresses everything in this thread.