Re: [Therion] Blended colour by gradient?
Hi Therion guys, I've had a go at this today, is there anyone who would be able to automate the repetitive process to enable the software to implement this itself for a projected elevation? and then add it as a background for a projected elevation survey. I've taken a look at the therion mailing list and can see replies, so thank you for those, i'm going to need to sort my emails so I see your replies again TH2 encoding utf-8 ##XTHERION## xth_me_area_adjust -129.0 -129.0 779.0 784.0 ##XTHERION## xth_me_area_zoom_to 400 scrap cusseygradientSE65 -projection [elevation 0] -scale [0 0 650 0 0.0 0.0 65 0.0 m] point 325.0 650.0 station -name 65 line wall -subtype invisible 650.0 645.0 650.0 655.0 endline line wall -subtype invisible 0.0 645.0 650.0 645.0 endline line wall -subtype invisible 650.0 655.0 0.0 655.0 endline line wall -subtype invisible 0.0 655.0 0.0 645.0 endline endscrap scrap cusseygradientSE64 -projection [elevation 0] -scale [0 0 650 0 0.0 0.0 65 0.0 m] point 325.0 640.0 station -name 64 line wall -subtype invisible 650.0 635.0 650.0 645.0 endline line wall -subtype invisible 650.0 645.0 0.0 645.0 endline line wall -subtype invisible 0.0 635.0 650.0 635.0 endline line wall -subtype invisible 0.0 645.0 0.0 635.0 endline endscrap scrap cusseygradientSE63 -projection [elevation 0] -scale [0 0 650 0 0.0 0.0 65 0.0 m] point 325.0 630.0 station -name 63 line wall -subtype invisible 0.0 625.0 650.0 625.0 endline line wall -subtype invisible 650.0 625.0 650.0 635.0 endline line wall -subtype invisible 650.0 635.0 0.0 635.0 endline line wall -subtype invisible 0.0 635.0 0.0 625.0 endline endscrap scrap cusseygradientSE62 -projection [elevation 0] -scale [0 0 650 0 0.0 0.0 65 0.0 m] line wall -subtype invisible 0.0 615.0 650.0 615.0 endline point 325.0 620.0 station -name 62 line wall -subtype invisible 650.0 615.0 650.0 625.0 endline line wall -subtype invisible 650.0 625.0 0.0 625.0 endline line wall -subtype invisible 0.0 625.0 0.0 615.0 endline endscrap scrap cusseygradientSE61 -projection [elevation 0] -scale [0 0 650 0 0.0 0.0 65 0.0 m] line wall -subtype invisible 0.0 605.0 650.0 605.0 endline point 325.0 610.0 station -name 61 line wall -subtype invisible 650.0 605.0 650.0 615.0 endline line wall -subtype invisible 650.0 615.0 0.0 615.0 endline line wall -subtype invisible 0.0 615.0 0.0 605.0 endline endscrap scrap cusseygradientSE60 -projection [elevation 0] -scale [0 0 650 0 0.0 0.0 65 0.0 m] point 325.0 600.0 station -name 60 line wall -subtype invisible 650.0 595.0 650.0 605.0 endline line wall -subtype invisible 650.0 605.0 0.0 605.0 endline line wall -subtype invisible 0.0 605.0 0.0 595.0 endline line wall 0.0 595.0 650.0 595.0 endline endscrap TH FILE survey cusseygradients centreline cs OSGB:SK station 65 "main ent." entrance fix 65 16350 75190 244 data normal from to length compass clino 0 1 1 0 90 1 2 1 0 90 2 3 1 0 90 3 4 1 0 90 4 5 1 0 90 5 6 1 0 90 6 7 1 0 90 7 8 1 0 90 8 9 1 0 90 9 10 1 0 90 10 11 1 0 90 11 12 1 0 90 12 13 1 0 90 13 14 1 0 90 14 15 1 0 90 15 16 1 0 90 16 17 1 0 90 17 18 1 0 90 18 19 1 0 90 19 20 1 0 90 20 21 1 0 90 21 22 1 0 90 22 23 1 0 90 23 24 1 0 90 24 25 1 0 90 25 26 1 0 90 26 27 1 0 90 27 28 1 0 90 28 29 1 0 90 29 30 1 0 90 30 31 1 0 90 31 32 1 0 90 32 33 1 0 90 33 34 1 0 90 34 35 1 0 90 35 36 1 0 90 36 37 1 0 90 37 38 1 0 90 38 39 1 0 90 39 40 1 0 90 40 41 1 0 90 41 42 1 0 90 42 43 1 0 90 43 44 1 0 90 44 45 1 0 90 45 46 1 0 90 46 47 1 0 90 47 48 1 0 90 48 49 1 0 90 49 50 1 0 90 50 51 1 0 90 51 52 1 0 90 52 53 1 0 90 53 54 1 0 90 54 55 1 0 90 55 56 1 0 90 56 57 1 0 90 57 58 1 0 90 58 59 1 0 90 59 60 1 0 90 60 61 1 0 90 61 62 1 0 90 62 63 1 0 90 63 64 1 0 90 64 65 1 0 90 endcentreline input cusseygradients.th2 map m1s -projection [elevation 0] cusseygradientSE65 cusseygradientSE64 cusseygradientSE63 cusseygradientSE62 cusseygradientSE61 cusseygradientSE60 endmap endsurvey Regards, Alastair Gott. From: alastair gott Sent: 07 October 2020 12:27 To: therion@speleo.sk Subject: Blended colour by gradient? Hi therion users, One of my friends has asked me whether it’s possible to colour an elevation survey by a blended gradient rather than a discrete scrap by scrap basis. I thought about it, but I don’t have the expertise in metapost, would it be possible to metapost a gradient which is predefined one colour through the normal rainbow of therion colours to the final colour and then bound this by the top and bottom of the cave. Then insert this gradient as a fill cave fg user. Just a thought? I know John Stevens has some good success with the Agen allwedd survey in South Wales (uk) but I think his solution relied upon the 1 colour for one scrap method, though my me
Re: [Therion] Blended colour by gradient?
> possible to colour an elevation survey But then I see that I may have misinterpreted the word "elevation". You may have meant projected elevation or extended elevation, rather than plan with elevation colouring. (Ambiguous words!) My answer still stands about metapost and gradients - it can do them. You would not need a reference station so much now though, because simple vertical position on the page would be enough, and it simplifies things a lot. It would still need to know the relative height of the top and bottom points of each scrap to know what colours to choose for the gradient lines (and while I know that can all be done with maths, I am glad I am not the one doing it, because that doesn't sound fun to me). But sadly, there are a great many things that would not actually work. There are a lot of "thclear" (clear this shape) and "thunfill" (un-fill this shape) commands used in the metapost, which do not just "make this part transparent". Instead, they re-paint the area with the colour of the scrap (this is because of how things get layered, and how some symbols are made from one colour, with what looks like a hole punched through them by another colour). If you had a gradient fill, those commands would not be able to choose a colour for that point. In other words, MetaPost can do gradients, but that is not compatible with the way that a lot of Therion works. ___ Therion mailing list Therion@speleo.sk https://mailman.speleo.sk/listinfo/therion
Re: [Therion] Blended colour by gradient?
As wrote Tarquin it is not possible. Try to make shorter scraps as Tarquin advice and divide long scraps. It is not simple work but it is possible. Martin ___ Therion mailing list Therion@speleo.sk https://mailman.speleo.sk/listinfo/therion
Re: [Therion] Blended colour by gradient?
> How should the bulge be coloured, given that its closest station within the > scrap is #3? As a caver, you would say 3 er ... 1 I knew what I meant. ___ Therion mailing list Therion@speleo.sk https://mailman.speleo.sk/listinfo/therion
Re: [Therion] Blended colour by gradient?
Hi Alastair, > One of my friends has asked me whether it’s possible to colour an elevation > survey by a blended gradient rather than a discrete scrap by scrap basis. As far as I know, the answer is "no", and I don't think it would actually be possible. It's not like Survex, where each line or 2D polygon can be shaded with a gradient, knowing the exact 3D altitude of each point within the polygon. Therion rendering is not made from polygons, it is made from a series of 2D vectors positioned arbitrarily around 3D points. Imagine that you have a scrap with 2 stations in it. How should each part of the scrap be coloured: The nearest station point within the scrap? Blended between the 2 nearest station points within a scrap? What about when the scrap protrudes beyond the last station? That's for a simple case. Now try 3 stations in a V shape. The point in the middle is equidistant from all of them. How should it blend? Does the wall beside it belong to the lowest station, the highest station or the middle one? Draw a line from the wall to one station. Should the colour change along that path? Imagine a simple passage with three stations. Start at station1. Go up a slope to station 2. Turn hard right and go up a slope to station 3. Scrap ends. At station 1, the right wall bulges out so from above, it looks like it almost touches station 3, but it does not connect. How should the bulge be coloured, given that its closest station within the scrap is #3? As a caver, you would say 3, but it would be a challenge to describe a solution for that to a computer program like Therion. > would it be possible to metapost a gradient Yes. Assuming you want linear gradients, not complex ones. Caves are complex. And Therion uses a 7 stage blend to get the rainbow effect. So you would have to be able to do much more than just a simple colour-from,colour-to gradient. > I think his solution relied upon the 1 colour for one scrap method Given the lengths of passage involved ("every passage in Aggy is twice as long as you want it to be" - Tarquin), that is how I would expect it to be done, and relatively easily too. This is why the general advice is to have each scrap cover a maximum of 5 metres of altitude within the cave. I would love for someone to prove me wrong though, because pure gradients within a cave survey sound awesome. ___ Therion mailing list Therion@speleo.sk https://mailman.speleo.sk/listinfo/therion
[Therion] Blended colour by gradient?
Hi therion users, One of my friends has asked me whether it’s possible to colour an elevation survey by a blended gradient rather than a discrete scrap by scrap basis. I thought about it, but I don’t have the expertise in metapost, would it be possible to metapost a gradient which is predefined one colour through the normal rainbow of therion colours to the final colour and then bound this by the top and bottom of the cave. Then insert this gradient as a fill cave fg user. Just a thought? I know John Stevens has some good success with the Agen allwedd survey in South Wales (uk) but I think his solution relied upon the 1 colour for one scrap method, though my memory could be wrong. Regards, Alastair Gott, alastairg...@hotmail.com Sent from my iPhone ___ Therion mailing list Therion@speleo.sk https://mailman.speleo.sk/listinfo/therion