How would you guy's make a roughness map for desert sand?
polycounter lvl 6
Maybe a stupid question but i Google this a bit without any success so is there anyone having some tips on this?
My first idea was to simply put a noise with few speckle of pure white to simulate the glittering but maybe i got this wrong!
My first idea was to simply put a noise with few speckle of pure white to simulate the glittering but maybe i got this wrong!
Replies
Check out:
http://advances.realtimerendering.com/s2012/
Abstract: In this talk, the author will describe the techniques used to create the dynamic sand dunes in PlayStation® Network title Journey. Specifically, the physics of footprints and trails will be discussed, as well as how to convey the sense of trillions of sparkling grains of sand on a TV that doesn't have the resolution to display them and a console that doesn't have the horsepower to render them.
Also check out their talk from GDC 2013
https://www.gdcvault.com/play/1017742/Sand-Rendering-in
So far i just have a basic physical material setup in 3ds max but i was wondering how would people approach roughness map creation for sand.
I know how pbr work but not sure about the correct way to do a sand roughness map.
Thank for the link will read them.
This is the render
And here is the roughness map i use
Agree i was thinking of using a procedural to get fewer white speckle and more dark grey to black , so maybe bercon maps could help with this.
https://support.allegorithmic.com/documentation/display/SDDOC/Dirt+3
If you're using spec/gloss, keep it as it is. For a gloss map, raise the black level slightly so it doesn't go pure black. Stick around 15 or 20 on a 255 scale. That will give you a very broad specular falloff for the body of the sand (which will help it feel soft), and then make the speckles pure white. For your specular map, duplicate your gloss map, but replace the white specks with color tints in the yellow-orange-red families. When your specular glints hits, it will return color instead of pure white which will feel much more like a reflection of light instead of white dots.
Lastly, make sure you are using a shader with a very broad diffuse BRDF and a fresnel term. This will also dramatically improve the softness.
Best of luck. Hope this is helpful
I'm sensing that you don't have or are not familiar with photoshop? Or Substance Painter?
Whatever the case is, there is free online sites where you can do basic image editing for free. Be sure to gather lots of reference of the specific type of sand you want to replicate. But besides the roughness, your rendered image looks like the procedural texture is too large to me -- more like dried dirt -- even if the specularity was altered.
Here the roughness map
Here a close up view of the roughness map
Now the real test is to put this material in UE4 and see what kind of voodoo will have to be done with the mip map to keep the sparkling effect working as intended.
Please comment since i think the normal map still a little strong and maybe the sand grain a bit too big.
This texture is a 4096x4096 example
Sand is a lot more tricky to get right than i initially thought but after all when you look at any games they all have their own representation of the ideal material but they face tech limitations like everyone else.
Already tile to maximum before losing every detail. When tiling it too much it's start to blur the noise so it's look just like there is no noise at all. Would need noise that is smaller than 1 pixel but that's wishful thinking!
tile 1
tile 5
tile 10
Thank now i just have to make 3 different size for the speckles since on the latest image i have only one small size speckle showing and desert sand have a wide spectrum of sparkle size. Will have to put them on top of a gradient to make them look better on various light angle.
After further test i did for my sparkles i found out that the best result is using only one tile sampler with polygon 1 as pattern input since i can control the intensity of the sparkle with the gradient setting.
I also tried various custom shapes i created in 3ds max to get variations with shade of greys but the result was not really convincing mainly because when scaling them to small realistic speckles they lost the details:
I made the size bigger to show the obvious difference between both methods here and i test both of them by walking around the area at various angle and you can clearly see in the image the result:
In motion it look a lot better so i will probably make a small video showing the effect.