A couple of questions, pretty basic ? Just can't find any info about these.

Started by Profane, June 17, 2015, 07:44:56 am

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Profane

Hello there people.
I have been doodling with terragen for way too long in the past months. And i'm never quite satisfied with my works.
[latest render as an attachment, just to show what my renders look currently]

So, to the questions. I'm sure these are fairly frequently asked ones but the thing that stops me from finding em is my grammar. I'm not a native speaker so i don't know the correct terms to use. Apologies.. :)

1. How do i add snow for example to the eroded/sloped parts of my terrains. Like in this photograph: http://i.imgur.com/n5uOdNN.jpg , i'm sure there is a way to do this. I have seen a couple of renders like this but can't really find em right now :/. I'm aware of maximum / minimum slopes etc, but it just doesn't quite cut it as you might imagine. Could painted shader be the answer ? Share your thoughts please :)

2. When using image map shader to.. lets say to some rocks on the beach that are really close to the camera. What would be the optimal settings for the "size" part ? I feel like if the size is 500x500 i seem to get blurry results no matter how big my image originally is. And if i make it 1x1 it looks okay but i feel like this shouldn't be done.. :D

3. When i want to change the color of an object, say.. grass for example. Is the correct way to change the color to go to the tab : Colour ->  tint diffuse colour -> an add an surface shader with a certain color there. Or is there a smarter way to do it ?

Thanks to everyone who bothers helping me. Feel free to ask questions if something is unclear, as i said i'm not a native speaker so no doubt there can be some.. hard to read text here.. :) Thank you !

Hannes

1. I guess you'll need a mix of altitude constraints, slope constraints and intersect underlying (under the effects tab of the surface layer. I attached a little example file.

2. There is no rule of thumb for the size. It depends on what's on your image. And of course on the projection type.

3. Example: the internal grass clump object. Go to the "Surface shaders"-tab, select the Default shader 01 (or whatever shader there is) and change the diffuse color to your color of choice.

Profane

Quote from: Hannes on June 17, 2015, 08:47:37 am
1. I guess you'll need a mix of altitude constraints, slope constraints and intersect underlying (under the effects tab of the surface layer. I attached a little example file.

2. There is no rule of thumb for the size. It depends on what's on your image. And of course on the projection type.

3. Example: the internal grass clump object. Go to the "Surface shaders"-tab, select the Default shader 01 (or whatever shader there is) and change the diffuse color to your color of choice.


_super_ helpful. Thanks a ton ! ^^

Dune

Quote3. Example: the internal grass clump object. Go to the "Surface shaders"-tab, select the Default shader 01 (or whatever shader there is) and change the diffuse color to your color of choice.

And to expand on this: if you want color variation you can use the settings in the population color variation, but also (which I always use) add a power fractal + a transform shader set to world/final position to the input of the mentioned default shader's color input. Use black and white or even color, or even a stack of PF's, if you want more/subtle variety in a population. Restrict it to slopes and heights if necessary by using masking by distribution or surface shader or feed the stack of PF's through the child layer of a surface shader before hauling through the transform shader and plug into that default shader's color input. Etc.

TheBadger

It has been eaten.


WAS

Quote from: Hannes on June 17, 2015, 08:47:37 am2. There is no rule of thumb for the size. It depends on what's on your image. And of course on the projection type.


To elaborate on this. the 1x1 is a 1:1 ratio in reality. So if you image is 500px by 500px then your 1:1 ratio is at the same. If you bring in a 4096px by 4096px image as your shader, your 1:1 ratio is at that size. At least from how I use image maps. I always use 1:1 and size in photoshop or whatever. Very rarely do I upscale within TG.

As to what the conversion between pixels and meters is within TG, I don't know.
Check out my Terragen Discord: https://discord.gg/Vy5FRTE

TheBadger

QuoteAs to what the conversion between pixels and meters is within TG, I don't know.


I can tell you that, in shades of grey, 1% is 1meter SO if you have a grey ramp, where black is 0% and white is 100%, then 0%=0meters and 100%=100meters. There is no fractions in PS in this regard (no half a %, so no half meter). Also, 1 pix will equal 1meter at 1:1 scale.

So, if you want steps, where each step is 1/2 a meter, then you would follow the above, and make the image map 50% scale in TG... In terms of height from 0base terrain, to the top of the displacement from the base terrain in altitude.
It has been eaten.

Oshyan

I'm pretty sure that's not quite correct Badger. In fact it is (or should be) pretty simple *by default*. IF you load a regular 8 bit image into a Heightfield Load node, it will treat every pixel as 1 meter, and every RGB brightness value as 1 meter. There are 256 brightness values (from 0 to 255), so your maximum terrain height in that case is 255m, which would be white, and the minimum is 0, black.

You *can* specify values in-between percentages (use the RGB values numerically, set them all the same, e.g. 6,6,6 is in-between 2 and 3 % brightness), in fact you want to for best accuracy. But more importantly *you are not limited to 8 bit*. We would actually strongly recommend working in 16 bit if possible (Photoshop does support this). You will get "stairstepping" and potentially poor results from 8 bit painted terrains.

- Oshyan

Dune

To add to this; in my museum wall part II, I used a 16bit painted heightfield (initially with a maximum 'whiteness' of an 30% grey {silly}), but the height difference is only 25 meters or so, so I decided to maximize the gamma from pure black to pure white, and resetting to 8-bit, resulting in 256 steps over 20-25 meters. Works well enough with some added displacement. So it depends on the height you need, whether its wise to use 8 or 16 bit.