At the beginning - yes, I read other topics about dark grass and it didn’t help.
I have a problem with GI using my 3D grass (3d model, spread with Skatter). As You can see, the shadows on the grass are very dark (almost pure black). I made a lot of tests and responsible for that is GI.
I changed textures, textures’ brightness, opacity mask, grass model, materials (foliage/generic) etc. Same result.
I work with auto exposure (48%), but when I turned it off and incresed value, the effect is like on image 3.png.
I tried to recreate Enscape grass, but Enscape grass behaves different. Is much brighter, doesn’t create black spots. When I looked from the top on each grass, on mine, I could see black circle. On Enscape grass circle is white. Enscape grass is also very bright when I looks on sun throught the grass (7.png). Both grasses look totally different in white mode.
The problem is not visible in draft mode, of course. (4.jpg). All screenshots made in Ultra quality.
Thank You for helping.
Edit: I add a few images with different exposure settings. See my next post below.
The Enscape grass takes the underlying texture and applied the colour value from it to the grass it’s self (Fill the ground with brick texture called “grass” and your grass will be coloured like the bricks under it). If you use a flat texture you will get boring grass - better to use a ‘hedge’ texture or something with variation.
If you do this as an under-lying texture for your own, then the black circle seen in 8 would be green.
I’m fairly sure that the difference in ‘white mode’ is because your grass has more edges than the Enscape grass.
Hi. Yes, I know how Enscape grass works. The problem is different. It looks like GI on my 3D grass (3d model, spread with Skatter) is calculated in different ways than on Enscape grass. I made a few test with different values of exposition. See the files below.
Thank You. Mail was sent. I prepard lighter version of the scene (scene from images was quite heavy), but the problem is still visible, of course.
File SKP = Sketchup 2017
I add also image of my Enscape3D settings.
Thanks, we’ve received your ticket! Here’s the reply for other users interested in the matter:
We could reproduce the issue and track down the cause. Unfortunately there’s no easy solution at the moment: The dark lighting is caused by false occlusion generated by the grass geometry itself. For our procedural built in grass we exclude this for the indirect light calculation via ray-tracing, therefore the issue doesn’t occur. If the grass is however is part of the scene geometry itself we can’t distinguish it from any other geometry and so it has an effect on indirect illumination. In the particular case of grass plane geometry with a mask texture the false occlusion originates from the fact that we don’t use the actual mask when ray-tracing the indirect light. So the whole plane of the grass geometry occludes.
We’ll see if we can come up with a solution for that issue in future versions. Right now one workaround could be to actually not use the Foliage material preset. This will result in worse shading in sunlight, but will look better in the shadows. Or you could of course use our built-in grass, which admittedly doesn’t look as convincing at the moment.
Or, just a thought, even try a mixture of both grass with no foliage material preset and the Enscape grass. That could help make it a more convincing rendering.
