After you clicked one of the buttons, open a node editor.

Here is a description of the materials with example images: LuxCoreRender Materials It offers several of the base materials with only one click.

However, you can also click one of the buttons in the panel below that is labeled 'Node Tree Presets'.

If you would click that, it would add a matte material (similar to Cycles' 'diffuse' shader).

You will now see a button called 'Use Material Nodes'.

Open the material tab in the properties:.

The world light source can be changed in the world panel. You can specify halt conditions to tell LuxCore to stop rendering after a certain amount of time, samples or noise level is reached, but this is only strictly required when you want to render an animation or multiple render layers (otherwise the first frame or the first render layer would render endlessly).Д«ecause the world in BlendLuxCore is set to a 'Sky' light by default.

Why is the render not stopping and the progress bar not filling?Д«y default, LuxCore renders endlessly until you press Esc to stop the render (when you are satisfied with the noise level).

We did not touch any materials yet, so they are converted with the fallback material that is supposed to tell you 'this object is missing a material (or node tree)'. In BlendLuxCore, every material should have an associated node tree.

This is Piita's Hungry for Light scene from the old LuxRender show-off pack

Luxcorerender blender 2.9