Thread by @delaneykingrox

#Gamedevtips graph based shader development tips:

A thread...

Its easy to make complex node graphs for shaders these days, and debugging can be a headache, especially if compile times are slow.

Make a "workbench" material and shader and just copy the bit that is killing your soul slowly in.
Once you get it right, copy/paste it back in.

"Static Switches" let you make variants to your shaders. But we warned... I have seen a few "tutorials" suggesting making a master shader with a bajilliom switches.

Let me explain binary to you.

1 switch = 2 shaders compiled ans stored.
2 switches = 4 shaders.
3 = 8
4 = 16

5 =32
6 =64
7 =128

Okay, so a few switches and you get much slower compile times and you have to store all the variants.

This can be bad in very tight memory or disk spaces.

However it is ok if you only load a few variants.

Rather than use the default unity shader, I always make my own. It gives me much faster workflow and more control.

For example, for PBR I pack my textures like unreal... metal, roughness and AO in one RGB map.

Your normal map green channel can be used to fake lighting from the top of flat wall by passing it into emission. You can use a power to control the falloff.

Saturate is a clamp from 0 to 1 that is done on the gpu... it has no performance it.

*hit.

UV inputs give you perfect gradients. You can use these to do a bajillion different effects, such as wipes, dissolves, text write-on, creating circles and so on.

Vertex colors is just four channels of float data from 0-1.

You can use this to drive anything from wetness, switching materials, exaggerating normal maps, blending on damage or straight up tinting something.

The formula for cool particle effects is...

(((Texture A x Texture B) x 2) x Texture C) x2.

Pan texture A uvs x2
Pan texture B uvs x1
Pan texture C uvs x 0.5 or use a still mask to limit the effect

A voronoi noise is a good start

Comment your shadersin detail as if you are talking to an idiot.

You will need to fix them months from now at stupid o'clock and you will be a grateful idiot.

I organise my node graphs horizontally in comment boxes that break up the workflow into texture coordinates, texture inputs, and then effects, finally assembling to the final material.
I place comment boxes containing disabled effects or prototyping parts beneath.

This way, I can zoom out and always know where things are relatively speaking.

Fpr Unity I use Amplify, which let's me plug values into a "register" variable" node, which I can then access using "get" nodes along the graph without having long wires messing up the place.

*for.

Register and get allows me to keep all the nodes in a comment box self contained. It gets values and masks and usually outputs a mask into a register node at the other end. So the box has no wires in or out.

This lets me keep stuff organised.

I use prefixes for variables so they are easy to find. For example, OUT_ is the final output that goes into the material.

Out_metallic
Out_albedo
Out_emissive
Etc

Others I use are...

Color_
VC_ (vertex color)
Mask_
Fader_

This sounds trivial, but if you use drop down boxes having them grouped by prefix stops you going insane.

Standard tricks you should learn:

Fresnel:
gives you how much the polygon is pointing towards you or at a glancing angle, with falloff controls.

Use
-Force shields, force bubbles.
-Fade a particle or poly before you get side on to it.
-reduce window reflections when face on

Offset map

Slides the UVs based on camera view angle. Basis of parralax occlusion mapping... just without the occlusion bit.

Use
-adding fake depth.
-fake interiors
-holographic guis

STEP

If A is less than B, gives you black. If B is equal or greater than A, gives you white.

Use
Wipes
Dissolves
Turning a single vertex paint channel into several material masks, saving you the other channels for effects.

SIN

Think sine wave going from 1 to -1 over the time you feed in. Or, basically smoothly oscillate, wibble, flash, blink.

Sin, Add 1, divide by 2 to get pulsing from 0 to 1.

Uses:
Wind on leaves
Computer lights
Warning colours on low health bars
Waves lapping on your toesies

ONE MINUS

Inverts a value, because a one minus any number is the inverse.

Use:
-Inverting the Y in a normal map because your artists have you direct x format when you use open gl.

-flipping your texture coordinates

-flip an alpha so you can multiply the effect on.

UV plus UV equals UV

Texture coordinates are just vector 2s... aka two floating numbers. Therefore you can maths them to do funky shit like distortions, making parts of a texture scroll, sampling a different part of a texture depending on another value or making walls melt

Just stick them back into a vector 2 before you plug that into a texture sample and you are gucci.

MULTIPLY

The workhorse of all shaders. Multiply anything by zero gives you zero, and by 1 gives you the original value. That's a dimmer switch, beotch.

Uses
-fuck tonnes.
-Multiply a white image with blood stains on it to get a decent blood effect.

MAKE PRETTY

A node that makes games look better. Plug art into this. Art is easy. Gamers who say we are lazy are right... we are just to stupid to use this node to make everything AAA.

HEIGHT LERP

This is a must for environment artists. Blend texture A with texture B, but use a height map version of B to reveal parts of A faster.

Use
Painting puddles into cobblestones
Painting mortar into bricks.

World position

Gives you the vertices position in the world as a float3 (x,y and z value.) Plug two of these into a UV slot (usually scaled down a bit) to get world position textures.

Use:
-Making floor textures seamless regardless of scale or rotation of mesh.
- room grunge

Vertex offset

Use to make stuff move, swell, shrink, wobble, undulate, throb and rustle.
Each vertex can be moved using maaaaaaaaaaaaths.

USE:
-Throbbing, swollen, wobbly, disgusting things.
-also things that are not republicans.
-wind in grass.

PLUMBUS:

Plug Shleem into Dinglebop, and it is pushed into the grumbo.

Uses:
-every house has one.

RENDER TEXTURE

Super useful trick, taking a camera image of something in the scene. That image can then be used in a shader to do... STUFFFS

Use
- get out of may way, grass!
- snow trails and foot prints!
- it doesn't rain inside.
-minimaps

CLIP
Discards a fragment (a pixel before it becomes a pixel). Makes shit vanish into the void. Poof... gone. Therefore cheaper than transparent things.

Use
-randomly hide parts of an npc's decorations.
-dissolve corpses
-spawn in
-put holes in things.

DITHER
Turns a value into a dotty pattern usually using a bayer pattern. Yunno how things like walls go transparent by turning into fine dots? That's dither. See clip as to why it is cheap.

Use
-see through shit on a tight budget.
-making retro pixel effects.

MILKSHAKE

Plugs boys to yard. I would teach you about this but I would have to charge.

Soeaking of charge. If I helped you go "aha!" Then take on me... take me on... I'll be gone in a day or twwwwoooooooooooooooooodonateToMyKoFi

ko-fi.com/dellak