Texturing geometry

Started by james adamson, August 21, 2020, 05:50:50 pm

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james adamson

Hi all.
I am retexturing some geometry from Evermotion.
The models have come in with mostly straight colour maps. i.e a building has a uv layout of the whole building but  mostly there are no separate spec
roughness passes etc. There is a broken windows image with alpha but I am not sure how to apply it in the default shader.
Without those extra elements I mentioned  would it still be worth applying specularity to say, a pile of rubble with no spec image. I have the image map and although it is not a b and w image it is greyscale. Could I use that in terragens default shader as a specularity image. And what are general settings? i.e for my building made of brick dirt plaster and rusted metal. I guess I set diffuse to 1 but how would I add a fresnel effect to say the smooth plaster? 
Apologies for the barrage of questions but I am totally new to the shading system. 
Cheers.
James.

luvsmuzik

We are now calling them shaders.....
So start in TG Materials Library https://planetside.co.uk/forums/index.php/board,56.0.html

There are many file shares here, tgc, that you may use on your models or examples of "how to" with image map shaders or image function 

Hannes has a material file share here with examples of metals and glass , carpaint glossy etc.
WAS has added many good textures recently, also.

Depending on the effect you want, some use reflective or glass shaders coupled with a transform input (world) piped directly to the material input node. 

Download a few shader clips and practice on a low poly model maybe; there are rules for textures but experimentation sometimes gives good results.

You will learn a lot from these texture combinations, merge options, transform possibilities, dissect them with trial and error. 

Last option, share your model and see if anyone will show you what they know. I am currently trying to figure out a texture layering system for some spacecraft, sooner or later I will succeed. Life is fun! :)

luvsmuzik

Okay so I went to Evermotion https://evermotion.org/shop/show_product/building-40-am234-archmodels/17314#

There I picked up AM 234_1 free dlld with agreement.

I loaded same model into Blender 2.83 and edited it to have glass windows. (Select faces, add new material, assign)

Export new obj. Load to Terragen. In material editor assign default material and new glass shader and transform input (world) 
I am working on trying to bump the default, I will show any progress.

Arch model 234_01.jpg

Dune

Nice buildings. Looks like you rendered in PT. I think the roughness of reflection needs to be set at zero, instead of 0.01, to get a crisper reflection in the windows, or render in standard.
If there's anything behind the windows, glass will be a wise choice, but if the building is empty, you might as well use the reflective shader.

sboerner

Looks good so far. Echo Dune's comments. Keep posting as you make progress.

james adamson

Hi. In my setup I am going to have loads and loads of object so I think I may avoid the glass shader as I think it may kill my machine.
And wow thanks for pointing me to the materials library I really had no idea you could do all that in Terragen. I didi not even know there was a glass shader :-[ Loads to experiment with. Thanks. Amazing stuff as well. Every day I find a whole new Terragen rabbit hole I could go down. I made a wrong connection
in my node graph the other day and what rendered was amazing. Nothing remotely what I was after or that could make any contribution to the job in hand but an amazing image nontheless.
Grabbing that model was amazingly proactive of you ;D . I guess my main issue with the colour map like you have there is how without any specular/roughness etc passes would one go about bringing that to life. all  I have are straight colour maps. I could take each colour map and break it down in PS and create passes that way but I have 108 models 21 of them are pretty complex buildings
and I simply do not have time so I am looking for a bit of shortcut if anyone has any ideas. There is only so much I can do in the comp.
Cheers.
James.

james adamson

Right I think I am getting somewhere. If I want to adjust colour map/image I must use an image map shader? Then colour adjust then saturation to produce spec/ref pass. Then feed that into the reflectivity function on the default shader? and remove the image
from the colour image input?
Is this a viable method for producing extra shading elements and then applying them? 
:o

sboerner

An image map shader can give you more flexibility, esp. if you want to adjust and desaturate. Never tried using it to generate additional texture maps though. Interesting idea.

If the color maps are generally consistent you can batch process them in Photoshop. Record an action to process each map then call it in the built-in batch script. (If you've never done this, it's easier than it sounds). PS could rip through 108 images in no time.

Do you need that many different models? You might be able to optimize by using fewer; for example, you could create a several pops for each model, with rotation values (min and max) locked at different points of the compass for each.

(Luvs, sorry if my previous post didn't make sense. Should know better than to multitask while online. :) )

james adamson

Hey.
I only have twenty or so buildings so I was going to look for a cheat to mix em up. I was going to post if there is a function to randomise rotation but in 90 degree amounts.
Sounds like there is but it is not obvious in the population dooda. How do I do that. I have also made one big grid which I was intending to do a sort of boolean thing on using fractal patterns or 
masks. So twenty variations of density shaders based off a few different rgb grids to make it as random as possible but all derived from one general building layout grid.
Photoshop thing sounds handy I will investigate. And yeah I guess its just a desat contrast and invert process. They do not need to be perfect just enough to liven them up.
There are going to be loads of em and mostly far away. The rest of the objects are debris and cars. Debris is very simple cars not so much but I have lots of elements for those.
No idea how I am gonna render any of this although I am amazed at how well TG copes with instances. Its super quick to render millions.
I wish you could feed more than one model into a population though like you can in Modo but you cant have everything.
Thanks for your input.
Cheers.

Dune

There is no way to randomize rotation over 90º.
From an image map you can indeed do a lot of changes; color adjust shader for adjusting tones, inverting; blue node desaturate, or convert-blue to scaler, etc. All can be used as masks for say a stack of empty surface shaders wich can carry reflective, or glass, or luminosity, or color, or displacement, finally fed into the object part.

james adamson

I thought that may be the case. Dang! 
Re the image map shader.... So I could use this method to create bumps/spec/roughness providing I had enough colour information in my source colour map? I would then use uv project in the image map shader to apply that to the part?

Dune

Not perfect, often the color map isn't very good to be translated into bump like in dark and light stones and medium color mortar. Light stones would stand out, darks would recede against the mortar, and that's not what you want. There are dedicated programs to do that, and even those can''t do that properly. I often have to hand-adjust bumpmaps.
I suggest testing it one a simple object, see what happens.
About the UV part, yes.

sboerner

QuoteThere is no way to randomize rotation over 90º.
Sorry I wasn't clear. I meant you could place several populations of the same object, aligning each population by "locking" Y rotation in 90-degree increments (min = max = 90, or min = max = 180, etc.) in the population shader. Or place several populations and set the rotation of each in the object loader. Or make several versions of each model with different rotations applied as you export them to OBJ.


Of course, you'll need a unique mask for each population to avoid overlapping instances.

james adamson

Re the elements creation.
Yeah i just need quick and rough for lots of distant objects to break them up a bit. So no bumps maps just spec fresnel type thing.  If there was not so much to do I would go the PS route
and do them cleanly.
And yep sorry I responded too hastily and actually digested your suggestion after replying. I have been really hoping there would be a way to do random rotation locked at 90 degree increments so thats what I saw in you reply. Wishful reading!

luvsmuzik

Here is a link to add to your image map education

https://planetside.co.uk/forums/index.php/topic,27563.0.html

sboerner adapts separate occlusion, height, reflection, base color images with this setup. 

As you said, we share and learn from each other. :)