Started by WAS, October 22, 2019, 05:45:52 pm
Quote from: Tangled-Universe on November 18, 2019, 06:35:06 amThat's an insane cloud, really cool!What's the cloud altitude and depth in this case? I see stepping goes all the way up to 20km altitude. While such extremes do exist it's usually up to around 12km.I guess render time is pretty long for such a large depth cloud layer?(Can't wait until the new threadrippers are released next week!)Quote from: Hetzen on October 29, 2019, 03:07:48 pmStep Start sets the black point, Step End sets the white point, is another way of looking at it. It's similar to how a Colour Adjust works when working with its black or white points in the Input Levels tab. If you move the black slider past the white, you'll see a similar 'flip'.Colour adjusts are my preferred nodes to perform these kind of selections.Besides using PF's as input for smooth steps is there any other reason why I should go for smooth step scalars instead of colour adjust?I like it that it's doing the job with just 1 node.@WAS Perhaps you already know, but it might still be valuable for others to know... Be aware that "get altitude" are world space values and "get altitude in texture" are specific for the element the node network eventually ends up, in this case a cloud.So if you have a cloud layer at 1000m altitude and 2000m depth (base = 0 meters and top = 2000 meters) then when using similar smooth step scalars the results are different between get altitude and get altitude in texture.Assume step start = 0Assumte step end = 2000If input = get altitude --> output is smooth gradient from 0 to 2000 meters in world space.If input = get altitude in texture ---> output is smooth gradient from cloud altitude to cloud altitude + 2000 meters, because the cloud's principle altitude of 1000m = 0 meters in texture space.To match the "get altitude" result you'd need to set step start to -1000 and step end to 1000.In turn this depends on whether you use the checkbox to keep textures when moving clouds.So before setting up any cloud work think ahead of what you intend to do with the cloud layer and (un)check the "keep texture when moving clouds" box or whatever it's called.This assures that should you decide to make your cloud movable that you don't have to recalculate and retransform your whole network, also for altitude.Personally I prefer to work this way by default.
Quote from: Hetzen on October 29, 2019, 03:07:48 pmStep Start sets the black point, Step End sets the white point, is another way of looking at it. It's similar to how a Colour Adjust works when working with its black or white points in the Input Levels tab. If you move the black slider past the white, you'll see a similar 'flip'.
Quote from: WAS on November 18, 2019, 01:11:06 pmThanks for the additional information. I did know this. One thing to keep in mind is texture space altitude keys do not relate to altitude heights.
Quote from: Tangled-Universe on November 19, 2019, 04:00:58 amQuote from: WAS on November 18, 2019, 01:11:06 pmThanks for the additional information. I did know this. One thing to keep in mind is texture space altitude keys do not relate to altitude heights. Ehhh...that was basically my whole story/point
Quote from: Hetzen on November 18, 2019, 05:14:39 pmGood to see you guys working with this setup.RogueNZ, those profile shapes are possible. One way would be to warp the position of a simple shape shader that has a soft edge using a Get Altitude to determine how it shifts along X or Z through Y. And apply 3 variants with TGD I posted.You would also need to shift the black and white points of that mask to give you the tapered profile. Colour Adjust does shift black and white points, but it does so statically, ie it doesn't change once set.So looking at the base of your shape, lets say we have a circular SSS with a radius of 1000m with a Linear edge thickness of 1000m. This node will have a pure white spot in the centre and pure black at its edge, with a linear greyscale ramp from edge to centre.What you can then do is use a Linear Step node to shift where black and white is within that circles ramp. Just as you can with a Colour Adjust shader. The difference being is the scalar inputs can be adjusted with further functions.In this example you could use one Linear Step with Get Altitude as its input to create a black point at 0m altitude and white at 500m ramp, which you would multiply by a fraction (0.2 for example) so the output would be 0 to 0.2 and you can use this output to be the black point of another Linear Step which has the SSS as its input. This will shift the black point of the SSS ramp through altitude 0 to 500, from 0 to 0.2. Giving you that tapered shape at the base of your example.The next step would be to do the same with the white point so that you have a constant falloff from edge to centre of the SSS disk. To do this, take the output of the Get Altitude/ Linear Step/ Muliply (0.2) you've just made and add another fraction (say 0.3) and plug that into Input 2 (the white point) of the Linear Step you used with the SSS input. This will give the profile 'solidity' in the centre and a feather edge of 0.3 all the way up through its altitude.You can then use that output to Multiply a Density Fractal, or plug it into the DFs mask input, same thing.
Quote from: Hetzen on November 19, 2019, 09:36:56 amI'm also wondering if this topic should be moved into the Function Node General area?
Quote from: Oshyan on November 19, 2019, 01:26:37 pmQuote from: Hetzen on November 19, 2019, 09:36:56 amI'm also wondering if this topic should be moved into the Function Node General area?I was thinking about that too. If you think it's a good fit, happy to do so.- Oshyan