Wet surfaces

GoingDown

I've been working on this scene for the past couple of weeks, and I'm at the point where I want to texture what I have before moving on with the modeling. I tend to stay motivated when I work in chunks like that. Unfortunately, texturing is one of my weaker points because my school apparently didn't feel like it was important. What I'm trying to do is make the scene look as though either it is currently raining, or it has just rained, so I want the surfaces to be wet and puddles on the ground, that sort of thing.

I kinda have a vague idea of how this could be accomplished, but I am looking for advice on how to do it. Should I do it with shaders, spec maps, diffuse? Any help or advice would be appreciated.

Revel

Wet surface..that's kinda hard. What I can think of right now is look for a shader (assuming you want to preview it in Max viewport) that support cube map, for example Xoliulshader or 3PointShader, and play around withe the reflection/ fresnel/ spec setting to achieve the desired result. It's tricky though, I haven't done it before, but I'm sure it's achievable with those great shaders...and a little bit of patient tweaking the setting hehe

EDIT: wait...apparently you're not using Max..sorry, you didn't mention what software you use, but judging from the viweport layout it looks like Maya. You can try to search the similar kind of shader for Maya like Xoliulshader or 3PointShader.

_Revel

Calabi

It doesnt really help you, but Darksiders has great wet surfaces. Water poring off statues and things. I think there are some developers here somewhere or maybe someone knows how they did it.

tda

Just make sure your spec and gloss maps are ramped way up and that makes things look wet. Puddles you could either add into textures with high spec and reflectivity, make decals the same way or make actual depressions in the ground and add floating planes with mostly transparent diffuse, a ripply normal and a reflection map.

If you wanted to go 1 step further you could set up a duplicate mesh that's pushed out slightly and use a xoliul or 3point material on it. Apply a watery ripple normalmap and a reflection to the mat, and animate the UV's to make the water flow down objects. Overkill unless you're planning to animate though.

Xoliul

My shader does work in Maya.

r_fletch_r

isnt there an example of this in the latest build of UDK. I think the GDC demo showed running water on stone walls.

sprunghunt

Yes the UDK GDC demo has a material with animated water flowing over it.

The general idea is to have a reflection map that is masked where the water is supposed to be.

Then you change the normal map depending on what kind of water it is. For example; a puddle is a flat spot on the normals.

kcayton

nice scene.

thoughts...

-look for pics of wet similar textures that may be in your scene or close to it.
-get lots of reference, but get photo reference, not just other cg examples.

-you can have the sweetest textures but, since shiny, wet surfaces are driven by lighting
and reflections of the environment and otherwise (i.e. hdr, ldr, etc.) they may not look
quite as nice with a default lighting/environment setup.
try 'roughing-in' some lighting, @ least the type of lighting you may use

something to keep in mind..

-undersides of objects may not be as wet (or as shiny) as other areas, etc.
-you can use noise maps to mix/fade materials like puddles to wet ground
-and rain and water usually do not have 100% mirror reflections

lookin' forward to seeing the updates..
-k

Calabi

Screenshot of the water in Darksiders, the water on the statue is constantly moving over and down off it.

Scruples

Without the animation it looks somewhat poor....I am sure it looks great ingame.

You can mask where the rain will fall using a shadowmap from a directional light pointing downwards...or more realistically a little to the side to simulate wind. You might want to increase the angle(size) of the light quite a bit to soften it, and bias the mask toward the rainy side.

It would be nice if there was a way to use it in conjunction with a curvature map to determine whether or not it will flow down a surface, because the above mentioned idea will work nicely with a bridge, but a statue or spherical object will need a different shader....assuming it is in the rain and not under the aforementioned bridge .

r_fletch_r

I wonder if you could do something similar to how old 80's/90's games did running water. namely pallette rotation with gradients. It could be time consuming but you would be able to define specific paths for trickles of water using luminance values. If you could create a 1-255 cycle or maybe a cosin wave linked to scene time and use that value +/- a certain range to create a mask from the gradient. You could store the gradient in the alpha channel of a texture or even create a rgb texture with different gradients running at different speeds.

http://www.effectgames.com/demos/canvascycle/?sound=1
http://www.effectgames.com/effect/article.psp.html/joe/Old_School_Color_Cycling_with_HTML5

Shadownami92

Couldn't this also be achieved using animated decals in UDK? You could either do that or also make a tilable gloss map and make it scroll (animated gloss map).

GoingDown

I figured it'd be mostly be using spec and reflectivity maps. I appreciate all the advice, I'm pretty awful at texturing because for some reason my stupid school decided to only dedicate 5 weeks of one class to texturing, but give me 6 animation classes in spite of being a modeler, because apparently textures aren't important.

So if I do a reflectivity map for a puddle, what would you recommend I do for the diffuse map where the puddle would be, would I paint the surface at all or would the spec and reflectivity maps look good enough. It's always hard to think what to color water when in reality it's transparent. I'm going to have a lot of stupid questions like this, I'm sure, but from where I'm coming from, I have next to no knowledge when it comes to textures. (Thanks Ai!)

Edit: And yeah, I'm working in Maya. I'm going to tackle learning Max as soon as I finish this scene.

StefanH

learn from the best...

http://www.neilblevins.com/cg_education/wet_materials/wet_materials.htm

Its non realitime. But you can apply similar principles to realtime.