How render 3D render texture in a Unity3D custom shader - unity3d

Hi is it possible to render a 3d render texture on a custom shader raymarching like a 3dtexture?
I use a 3D render texture because I calculate and set the color of the 3D volume in a compute shader. I set the rendertexture 3D as shown below:
output3DRenderTexture= new RenderTexture(m_CubeDim.x, m_CubeDim.y, 0, thisTexFormat);
outpuoutput3DRenderTextureRendTex.enableRandomWrite = true;
output3DRenderTexture.dimension = UnityEngine.Rendering.TextureDimension.Tex3D;
output3DRenderTexture.volumeDepth = m_CubeDim.z;
output3DRenderTexture.Create();
I populate the 3D RenderTexture data in a a compute shader and GetData helps me confirm the 3d render texture has all the correct color data.
I can successfully render if I replace the 3D renderTex in the custom shader's sampler3D for a 3DTexture I create with the Tex2D slices.
cubeRenderer.material.SetTexture("_MainTex", output3DRenderTexture);//this does not render
versus
cubeRenderer.material.SetTexture("_MainTex", outputTexture3D);//this renders
This post in 2016 seems to suggest it's possible to render 3d render textures in custom shaders but it may now be outdated, it doesn't work for me and no error shows either.
It seems to me there maybe a significant performance hit if create the Textures2D slices in GPU, carry on with the creation of the Texture3D on CPU and re-send this Tex3D to GPU for the custom shader to consume it. After all the 3D volume already existed in GPU except as RenderTexture set as Tex3D. Thank you!
Shader:
#include "UnityCG.cginc"
#define ITERATIONS 100
#define PI2 6.28318530718
half4 _Color;
sampler3D _MainTex;
half _Intensity, _Threshold;
half3 _SliceMin, _SliceMax;
float4x4 _AxisRotationMatrix;
float _Angle;
struct Ray {
float3 origin;
float3 dir;
};
struct AABB {
float3 min;
float3 max;
};
// https http.download.nvidia.com/developer/presentations/2005/GDC/Audio_and_Slides/VolumeRendering_files/GDC_2_files/GDC_2005_VolumeRenderingForGames_files/Slide0073.htm
bool intersect(Ray r, AABB aabb, out float t0, out float t1)
{
float3 invR = 1.0 / r.dir;
float3 tbot = invR * (aabb.min - r.origin);
float3 ttop = invR * (aabb.max - r.origin);
float3 tmin = min(ttop, tbot);
float3 tmax = max(ttop, tbot);
float2 t = max(tmin.xx, tmin.yz);
t0 = max(t.x, t.y);
t = min(tmax.xx, tmax.yz);
t1 = min(t.x, t.y);
return t0 <= t1;
}
float3 get_uv(float3 p) {
return (p + 0.5);
}
float sample_volume(float3 uv, float3 p)
{
float v = tex3D(_MainTex, uv).r * _Intensity;
return v;
}
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float4 vertex : SV_POSITION;
float2 uv : TEXCOORD0;
float3 world : TEXCOORD1;
float3 local : TEXCOORD2;
};
v2f vert(appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = v.uv;
o.world = mul(unity_ObjectToWorld, v.vertex).xyz;
o.local = v.vertex.xyz;
return o;
}
fixed4 frag(v2f i) : SV_Target
{
Ray ray;
ray.origin = i.local;
// world space direction to object space
float3 dir = (i.world - _WorldSpaceCameraPos);
ray.dir = normalize(mul(unity_WorldToObject, dir));
AABB aabb;
aabb.min = float3(-0.5, -0.5, -0.5);
aabb.max = float3(0.5, 0.5, 0.5);
float tnear;
float tfar;
intersect(ray, aabb, tnear, tfar);
tnear = max(0.0, tnear);
// float3 start = ray.origin + ray.dir * tnear;
float3 start = ray.origin;
float3 end = ray.origin + ray.dir * tfar;
float dist = abs(tfar - tnear);
float step_size = dist / float(ITERATIONS);
float3 ds = normalize(end - start) * step_size;
float4 dst = float4(0, 0, 0, 0);
float3 p = start;
[unroll]
for (int iter = 0; iter < ITERATIONS; iter++)
{
float3 uv = get_uv(p);
float v = sample_volume(uv, p);
float4 src = float4(v, v, v, v);
src.a *= 0.5;
src.rgb *= src.a;
// blend
dst = (1.0 - dst.a) * src + dst;
p += ds;
if (dst.a > _Threshold) break;
}
return saturate(dst) * _Color;
}
#endif

Related

How to design a shader in Unity so it uses directions from the camera

I have found a few unique shaders from Shadertoy which I would like to impart an experience of 'sky' within models of buildings in Unity AR.
An example might be this one: https://www.shadertoy.com/view/4tdSWr which is just the sky looking up, or this one, https://www.shadertoy.com/view/4tdSWr which has some directional input from the mouse (click and drag) - the HLSL/unity version of this code except for changes to mouse input is at the end of this post.
Right now the clouds feel more like a green screen projection on the model, so there is no implication of direction or horizon if you are looking parallel to the plane the building is on. (ie, if I am standing with the clouds moving from right to left, as I turn left they don't appear to be moving from behind me and receding into the distance)
I have been trying to understand how to use the camera to 'rotate' the shader result so the direction of the camera is used to ensure the direction of the clouds movement. I would also like to use the angle of the camera with respect to the ground plane to impart a horizon when you are looking out towards the walls.
Any insight on how to do this would be great, especially if it is more than just a 'use _WorldSpaceCameraPos' or 'just add UNITY_MATRIX_MVP' as the results I found through excessive googling haven't really been that helpful so far.
The code for the second shader linked, adjusted for HLSL/Unity except for the mouse inputs is at the end of this post.
Shader "Unlit/skybox"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
iChannel0 ("noise-image", 2D) = "noise-image.png" {}
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 100
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
// make fog work
#pragma multi_compile_fog
#include "UnityCG.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float2 uv : TEXCOORD0;
UNITY_FOG_COORDS(1)
float4 vertex : SV_POSITION;
};
sampler2D _MainTex;
sampler2D iChannel0;
float4 _MainTex_ST;
float random(in float2 uv)
{
return tex2D(iChannel0, uv / 64.).r;
}
float noise(in float2 uv)
{
float2 i = floor(uv);
float2 f = frac(uv);
f = f * f * (3. - 2. * f);
float lb = random(i + float2(0., 0.));
float rb = random(i + float2(1., 0.));
float lt = random(i + float2(0., 1.));
float rt = random(i + float2(1., 1.));
return lerp(lerp(lb, rb, f.x),
lerp(lt, rt, f.x), f.y);
}
#define OCTAVES 8
float fbm(in float2 uv)
{
float value = 0.;
float amplitude = .5;
for (int i = 0; i < OCTAVES; i++)
{
value += noise(uv) * amplitude;
amplitude *= .5;
uv *= 2.;
}
return value;
}
float3 Sky(in float3 ro, in float3 rd)
{
const float SC = 1e5;
// Calculate sky plane
float dist = (SC - ro.y) / rd.y;
float2 p = (ro + dist * rd).xz;
p *= 1.2 / SC;
// from iq's shader, https://www.shadertoy.com/view/MdX3Rr
float3 lightDir = normalize(float3(-.8, .15, -.3));
float sundot = clamp(dot(rd, lightDir), 0.0, 1.0);
float3 cloudCol = float3(1.,1.0,1.0);
//float3 skyCol = float3(.6, .71, .85) - rd.y * .2 * float3(1., .5, 1.) + .15 * .5;
float3 skyCol = float3(0.3,0.5,0.85) - rd.y*rd.y*0.5;
skyCol = lerp( skyCol, mul(0.85, float3(0.7,0.75,0.85)), pow( 1.0 - max(rd.y, 0.0), 4.0 ) );
// sun
float3 sun = mul(mul(0.25 , float3(1.0,0.7,0.4)) , pow( sundot,5.0 ));
sun += mul(mul(0.25 , float3(1.0,0.8,0.6)) , pow( sundot,64.0 ));
sun += mul(mul(0.2 , float3(1.0,0.8,0.6)) , pow( sundot,512.0 ));
skyCol += sun;
// clouds
float t = mul(_Time.y , 0.1);
float den = fbm(float2(p.x - t, p.y - t));
skyCol = lerp( skyCol, cloudCol, smoothstep(.4, .8, den));
// horizon
skyCol = lerp( skyCol, mul(0.68 , float3(.418, .394, .372)), pow( 1.0 - max(rd.y, 0.0), 16.0 ) );
return skyCol;
}
float3x3 setCamera( in float3 ro, in float3 ta, float cr )
{
float3 cw = normalize(ta-ro);
float3 cp = float3(sin(cr), cos(cr),0.0);
float3 cu = normalize( cross(cw,cp) );
float3 cv = normalize( cross(cu,cw) );
return float3x3( cu, cv, cw );
}
void mainImage( out float4 fragColor, in float2 fragCoord )
{
float2 uv = fragCoord.xy / _ScreenParams.xy;
uv -= 0.5;
uv.x *= _ScreenParams.x / _ScreenParams.y;
float2 mouse = iMouse.xy/_ScreenParams.xy;
float3 ro = float3(0.0, 0.0, 0.0);
float3 ta = float3(cos(mul(mouse.x , 6.28)), mul(mouse.y , 2.0), sin(mul(mouse.x , 6.28)));
float3x3 cam = setCamera(ro, ta, 0.0);
float3 rd = normalize(mul(cam , float3(uv, 1.0)));
float3 col = Sky(ro, rd);
fragColor = float4(float3(col),1.0);
}
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
UNITY_TRANSFER_FOG(o,o.vertex);
return o;
}
fixed4 frag (v2f i) : SV_Target
{
// sample the texture
fixed4 col = tex2D(_MainTex, i.uv);
// apply fog
UNITY_APPLY_FOG(i.fogCoord, col);
return col;
}
ENDCG
}
}
}

Dynamically recalculating normals after vertex displacement

Can anyone let me know if I'm on the right tack with this: I have a vertex shader that bumps outward dynamically depending on a point passed in (think a mouse running under a rug). In order for the lighting to update properly, I need to recalculate the normals after modifying the vertex position. I have access to each vertex point as well as the origin.
My current thinking is I do some sort of math to determine the tangent / bitangent and use a cross product to determine the normal. My math skills aren't great, what would I need to do to determine those vectors?
Here's my current vert shader:
void vert(inout appdata_full v)
{
float3 worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
float distanceToLift = distance(worldPos, _LiftOrigin);
v.vertex.y = smoothstep(_LiftHeight, 0, distanceToLift / _LiftRadius) * 5;
}
A simple solution is covered in this tutorial by Ronja, which I'll summarize here with modifications which reflect your specific case.
First, find two points offset from your current point by a small amount of tangent and bitangent (which you can calculate from normal and tangent):
float3 posPlusTangent = v.vertex + v.tangent * 0.01;
worldPos = mul(unity_ObjectToWorld, posPlusTangent).xyz;
distanceToLift = distance(worldPos, _LiftOrigin);
posPlusTangent.y = smoothstep(_LiftHeight, 0, distanceToLift / _LiftRadius) * 5;
float3 bitangent = cross(v.normal, v.tangent);
float3 posPlusBitangent = v.vertex + bitangent * 0.01;
worldPos = mul(unity_ObjectToWorld, bitangent).xyz;
distanceToLift = distance(worldPos, _LiftOrigin);
posPlusBitangent.y = smoothstep(_LiftHeight, 0, distanceToLift / _LiftRadius) * 5;
Then, find the difference between these offsets and the new vertex pos to find the new tangent and bitangent, then do another cross product to find the resulting normal:
float3 modifiedTangent = posPlusTangent - v.vertex;
float3 modifiedBitangent = posPlusBitangent - v.vertex;
float3 modifiedNormal = cross(modifiedTangent, modifiedBitangent);
v.normal = normalize(modifiedNormal);
Altogether:
float find_offset(float3 localV)
{
float3 worldPos = mul(unity_ObjectToWorld, localV).xyz;
float distanceToLift = distance(worldPos, _LiftOrigin);
return smoothstep(_LiftHeight, 0, distanceToLift / _LiftRadius) * 5;
}
void vert(inout appdata_full v)
{
v.vertex.y = find_offset(v.vertex);
float3 posPlusTangent = v.vertex + v.tangent * 0.01;
posPlusTangent.y = find_offset(posPlusTangent);
float3 bitangent = cross(v.normal, v.tangent);
float3 posPlusBitangent = v.vertex + bitangent * 0.01;
posPlusTangent.y = find_offset(posPlusBitangent);
float3 modifiedTangent = posPlusTangent - v.vertex;
float3 modifiedBitangent = posPlusBitangent - v.vertex;
float3 modifiedNormal = cross(modifiedTangent, modifiedBitangent);
v.normal = normalize(modifiedNormal);
}
This is a method of approximation, but it may be good enough!

Shader works in Editor but not on iPhone

I am using the next script for a painting asset found on this website.
As you render the faces of your mesh in the uv space of the mesh, you are reconstruction the islands one triangle at the time. On the edges of the island, it can be that due to underestimation the rasterizer doesn’t consider a pixel which is actually in the island. For these pixels, no pixel shader will be executed and you will be left over with a crease. (text and image taken form the website)
The basic idea is that every frame, after the paint texture has been updated, I run a shader over the entire texture, and using a filter and a pre baked mask of the uv islands, extend the islands outwards.
The problem is that it does not work on iPhone. There is no error, no weird coloring, it is like that script does not get applied. I am not sure where the problem is coming from..maybe the for loops or the command buffers used in c#.
Shader "Unlit/FixIlsandEdges"
{
SubShader
{
// =====================================================================================================================
// TAGS AND SETUP ------------------------------------------
Tags { "RenderType"="Opaque" }
LOD 100
Pass
{
// =====================================================================================================================
// DEFINE AND INCLUDE ----------------------------------
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
// =====================================================================================================================
// DECLERANTIONS ----------------------------------
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
};
sampler2D _MainTex;
uniform float4 _MainTex_TexelSize;
sampler2D _IlsandMap;
// =====================================================================================================================
// VERTEX FRAGMENT ----------------------------------
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = v.uv;
return o;
}
fixed4 frag (v2f i) : SV_Target
{
fixed4 col = tex2D(_MainTex, i.uv);
float map = tex2D(_IlsandMap,i.uv);
float3 average = col;
if (map.x < 0.2) { // only take an average if it is not in a uv ilsand
int n = 0;
average = float3(0., 0., 0.);
for (float x = -1.5; x <= 1.5; x++) {
for (float y = -1.5; y <= 1.5; y++) {
float3 c = tex2D(_MainTex, i.uv + _MainTex_TexelSize.xy*float2(x, y));
float m = tex2D(_IlsandMap, i.uv + _MainTex_TexelSize.xy*float2(x, y));
n += step(0.1, m);
average += c * step(0.1, m);
}
}
average /= n;
}
col.xyz = average;
return col;
}
ENDCG
}
}
}
I've read somewhere that using tex2D in for loops is a big no no, so I changed that to a tex2Dlod but the same thing happens.
You can check out the Git project here
I am completely lost on this one and google isn't very helpful. Thank you for any comments.

Shader that transforms a mercator projection to equirectangular?

I am trying to make a shader in Unity taking a mercator projection texture as a source and converting it to an equirectangular projection texture.
Input example:
Output example:
This example does the opposite with an equirectangular as source.
If you look at the source of the above example:
// mercator
float latClamped = clamp(lat, -1.4835298641951802, 1.4835298641951802);
float yMerc = log(tan(PI / 4.0 + latClamped / 2.0)) / PI2;
float xMerc = xEqui / 2.0;
vec4 mercatorPos = vec4(xMerc, yMerc, 0.0, 1.0);
Can anyone help to reverse this so I'm able to go from a mercator map as a source to equirectangular (or even better, azimuthal).
Looking for a way to do 2D texture deformations going from x/y to longitude(x)/latitude(y) and back.
I appreciate your input.
If you want to output the equirectangular projection, you need to convert from equirectangular coordinates to mercator coordinates and then sample the mercator projection at those coordinates.
This is what it would look like in a fragment shader from uvs:
//uv to equirectangular
float lat = (uv.x) * 2 * PI; // from 0 to 2PI
float lon = (uv.y - .5f) * PI; // from -PI to PI
// equirectangular to mercator
float x = lat;
float y = log(tan(PI / 4. + lon / 2.));
// bring x,y into [0,1] range
x = x / (2*PI);
y = (y+PI) / (2*PI);
// sample mercator projection
fixed4 col = tex2D(_MainTex, float2(x,y));
The same thing applies to the azimuthal projection: You can go from azimuthal coordinates -> equirectangular -> mercator and sample the image. Or you can find a formula to go directly from azimuthal -> mercator. The wiki pages have a bunch of formulas to go back and forth between projections. Here is a full shader to play around with. Input is a mercator projection and outputs a equirectangular or azimuthal projection (choose from the dropdown menu)
Shader "Unlit/NewUnlitShader 1"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
[Enum(Equirectangular,0,Azimuthal,1)]
_Azimuthal("Projection", float) = 0
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 100
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
};
sampler2D _MainTex;
float4 _MainTex_ST;
float _Azimuthal;
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
return o;
}
#define PI 3.141592653589793238462f
#define PI2 6.283185307179586476924f
float2 uvToEquirectangular(float2 uv) {
float lat = (uv.x) * PI2; // from 0 to 2PI
float lon = (uv.y - .5f) * PI; // from -PI to PI
return float2(lat, lon);
}
float2 uvAsAzimuthalToEquirectangular(float2 uv) {
float2 coord = (uv - .5) * 4;
float radius = length(coord);
float angle = atan2(coord.y, coord.x) + PI;
//formula from https://en.wikipedia.org/wiki/Lambert_azimuthal_equal-area_projection
float lat = angle;
float lon = 2 * acos(radius / 2.) - PI / 2;
return float2(lat, lon);
}
fixed4 frag(v2f i) : SV_Target
{
// get equirectangular coordinates
float2 coord = _Azimuthal ? uvAsAzimuthalToEquirectangular(i.uv) : uvToEquirectangular(i.uv);
// equirectangular to mercator
float x = coord.x;
float y = log(tan(PI / 4. + coord.y / 2.));
// brin x,y into [0,1] range
x = x / PI2;
y = (y + PI) / PI2;
fixed4 col = tex2D(_MainTex, float2(x,y));
// just to make it look nicer
col = _Azimuthal && length(i.uv*2-1) > 1 ? 1 : col;
return col;
}
ENDCG
}
}
}

Merging 2 shaders

I am currently using 2017.3.0f.3. I have two CG shaders that I would like to merge into a single shader. One is for handling the distortion of a sprite (like waves/wind), the other keeps it facing the camera (billboard). They work independently but I need them to work together.
Shader 1:
Shader "Cg shader for billboards" {
Properties {
_MainTex ("Texture Image", 2D) = "white" {}
_ScaleX ("Scale X", Float) = 1.0
_ScaleY ("Scale Y", Float) = 1.0
}
SubShader {
Pass {
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
// User-specified uniforms
uniform sampler2D _MainTex;
uniform float _ScaleX;
uniform float _ScaleY;
struct vertexInput {
float4 vertex : POSITION;
float4 tex : TEXCOORD0;
};
struct vertexOutput {
float4 pos : SV_POSITION;
float4 tex : TEXCOORD0;
};
vertexOutput vert(vertexInput input)
{
vertexOutput output;
output.pos = mul(UNITY_MATRIX_P,
mul(UNITY_MATRIX_MV, float4(0.0, 0.0, 0.0, 1.0))
+ float4(input.vertex.x, input.vertex.y, 0.0, 0.0)
* float4(_ScaleX, _ScaleY, 1.0, 1.0));
output.tex = input.tex;
return output;
}
float4 frag(vertexOutput input) : COLOR
{
return tex2D(_MainTex, float2(input.tex.xy));
}
ENDCG
}
}
}
Shader 2:
Shader "Transparent/Cutout/Diffuse Shake" {
Properties {
_Color ("Main Color", Color) = (1,1,1,1)
_MainTex ("Base (RGB) Trans (A)", 2D) = "white" {}
_Cutoff ("Alpha cutoff", Range(0,1)) = 0.5
_ShakeDisplacement ("Displacement", Range (0, 1.0)) = 1.0
_ShakeTime ("Shake Time", Range (0, 1.0)) = 1.0
_ShakeWindspeed ("Shake Windspeed", Range (0, 1.0)) = 1.0
_ShakeBending ("Shake Bending", Range (0, 1.0)) = 1.0
}
SubShader {
Tags {"Queue"="AlphaTest" "IgnoreProjector"="True" "RenderType"="TransparentCutout"}
LOD 200
CGPROGRAM
#pragma target 3.0
#pragma surface surf Lambert alphatest:_Cutoff vertex:vert addshadow
sampler2D _MainTex;
fixed4 _Color;
float _ShakeDisplacement;
float _ShakeTime;
float _ShakeWindspeed;
float _ShakeBending;
struct Input {
float2 uv_MainTex;
};
void FastSinCos (float4 val, out float4 s, out float4 c) {
val = val * 6.408849 - 3.1415927;
float4 r5 = val * val;
float4 r6 = r5 * r5;
float4 r7 = r6 * r5;
float4 r8 = r6 * r5;
float4 r1 = r5 * val;
float4 r2 = r1 * r5;
float4 r3 = r2 * r5;
float4 sin7 = {1, -0.16161616, 0.0083333, -0.00019841} ;
float4 cos8 = {-0.5, 0.041666666, -0.0013888889, 0.000024801587} ;
s = val + r1 * sin7.y + r2 * sin7.z + r3 * sin7.w;
c = 1 + r5 * cos8.x + r6 * cos8.y + r7 * cos8.z + r8 * cos8.w;
}
void vert (inout appdata_full v) {
float factor = (1 - _ShakeDisplacement - v.color.r) * 0.5;
const float _WindSpeed = (_ShakeWindspeed + v.color.g );
const float _WaveScale = _ShakeDisplacement;
const float4 _waveXSize = float4(0.048, 0.06, 0.24, 0.096);
const float4 _waveZSize = float4 (0.024, .08, 0.08, 0.2);
const float4 waveSpeed = float4 (1.2, 2, 1.6, 4.8);
float4 _waveXmove = float4(0.024, 0.04, -0.12, 0.096);
float4 _waveZmove = float4 (0.006, .02, -0.02, 0.1);
float4 waves;
waves = v.vertex.x * _waveXSize;
waves += v.vertex.z * _waveZSize;
waves += _Time.x * (1 - _ShakeTime * 2 - v.color.b ) * waveSpeed *_WindSpeed;
float4 s, c;
waves = frac (waves);
FastSinCos (waves, s,c);
float waveAmount = v.texcoord.y * (v.color.a + _ShakeBending);
s *= waveAmount;
s *= normalize (waveSpeed);
s = s * s;
float fade = dot (s, 1.3);
s = s * s;
float3 waveMove = float3 (0,0,0);
waveMove.x = dot (s, _waveXmove);
waveMove.z = dot (s, _waveZmove);
v.vertex.xz -= mul ((float3x3)_World2Object, waveMove).xz;
}
void surf (Input IN, inout SurfaceOutput o) {
fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
o.Albedo = c.rgb;
o.Alpha = c.a;
}
ENDCG
}
Fallback "Transparent/Cutout/VertexLit"
}
I have tried a failed multiple times already. Is it possible?
It is possible, and there's more than one way to go:
The simplest would be to not use the billboard shader at all and just orient the transform to look at the camera using a c# script. If you are not looking into efficiency, this is the best solution.
The other solution is to merge the wave function into the vertex shader of the billboard one. You just need to apply the wave distortion before the billboard transformation:
input.vertex.xz -= mul ((float3x3)_World2Object, waveMove).xz;
output.pos = mul(UNITY_MATRIX_P,
mul(UNITY_MATRIX_MV, float4(0.0, 0.0, 0.0, 1.0))
+ float4(input.vertex.x, input.vertex.y, 0.0, 0.0)
* float4(_ScaleX, _ScaleY, 1.0, 1.0));
(you ofc need to move everything related to waveMove along with it :) )
If you need the lighting to work (the benefit of using surface shader), then it gets trickier. Surface shaders transform into clip/screen space behind the scene, after the execution of your main vertex shader method. Since billboard transformation needs to break down that transformation things get messy: you need to transform the vertices into their final clip space position, and then convert it back into object space so it can be re-transformed again behind the scene into the desired position.