LuxCoreRender Forums

Sharlybg wrote: ↑Fri Mar 08, 2019 9:17 am object relative size

What's does it mean?

Look, there's black and white map. Curb length is 1 meter; ball diameter is 10 cm. Bump height is 80 cm! And if I set it to anything below 10 cm, bump just disappear. ~
But if I remap the map to values from 0.5 to 1.0, bump height has to be just 2mm. ~
And if I use HDRI, these values has to be 3-4 times lower. Which is also an issue.
Height difference would be around 1cm in real world. Particle size can differ, in my file it's 1cm.

Object size compared to blender unit/real viewport size and the way luxcore compute object size. this Size probleme happen mostly when object are upscaled in edit mode and then Downscaled in object mode.

Look at theses cubes they share the same viewport size "2m" but due to upscale x10 in edit mode and dowscale in object mode x0.1 the cube at the right size is now 20cm in reality and i suppose it will be the same in luxcore. so bump of same value will not look the same on both cube.

I made once an experience with extreme up and down scaling. Up to 10 km and back to 1 m. It screwed my objects. They look well in wireframe. But rendering lead to bad terminator effects.

I thought this has to do with floating point precision.

Quite strange that effect you posted that sizing in edit mode and object mode has a different effect on size.

Do you have an explanation?

Sharlybg wrote: ↑Thu Mar 07, 2019 8:36 am Don't think it is fair to compare luxcore to cycles with 128 path deph for cycles and just 10 max for lux. if you want good comparison try to simulate exactly same setting for each renderer : Cameera/light / engine.

I've found that with the default 8 bounce Cycles settings there is virtually no GI.

wasd wrote: ↑Thu Mar 07, 2019 12:27 pm Cycles has no bidir, nor Metropolis. It's just of of league.
p.s. cycles has bump. luxcore has NO bump

Just use normal maps, Substance and other programs export them automatically, most texture download sites offer them, CrazyBump can generate them easily from an input color image.

wasd wrote: ↑Fri Mar 08, 2019 11:06 am Look, there's black and white map. Curb length is 1 meter; ball diameter is 10 cm. Bump height is 80 cm! And if I set it to anything below 10 cm, bump just disappear.

But if I remap the map to values from 0.5 to 1.0, bump height has to be just 2mm.

And if I use HDRI, these values has to be 3-4 times lower. Which is also an issue.
Height difference would be around 1cm in real world. Particle size can differ, in my file it's 1cm.

Maybe a look from a different view, instead of looking for flaws, do what makes it look as close as possible to your intended goal.
For example, i prefer to consider textures (for bump & displacement) "Height maps" also, use better textures to visually fill in where LC2 lacks

kintuX wrote: ↑Sat Mar 09, 2019 11:47 am Maybe a look from a different view, instead of looking for flaws, do what makes it look as close as possible to your intended goal.

But I don't looking for flaws, it's flaws come looking for me!
When I must use bump, I do normal maps, them working fine. It's just I'm a bit frustrated when height map can't do bump for me.

Lux interior renders look more realistic and appealing than Cycles; IMHO: Just look at the attached render by lacilaci (from a screen snippet) Mind blowing stuff, right! : I haven't seen any interiors look as realistic in Cycles - in fact I haven't seen anything that even comes close! Maybe lacilaci is an interior genius, but it takes 2 to tango - software and artist.

I'm not saying Lux is better than than Cycles, just that Lux looks more realistic to me!

Anyway, that's my pennies worth of thought on the topic of: ' Comparison Between Lux and Cycles'

wasd wrote: ↑Sat Mar 09, 2019 1:41 pm But I don't looking for flaws, it's flaws come looking for me!
When I must use bump, I do normal maps, them working fine. It's just I'm a bit frustrated when height map can't do bump for me.

It's just a bump effect, so really there's nothing too excessive to expect (alike displacement). Yes, also Normal maps perform slightly better.
In case above i adapted the noise size & plugged it into Height input (effect is already bordering on precision issues, comes obvious if you zoom out - look at the great picture)
As mentioned, do better work with textures, filling in details where "simulation" can't help.