shader with manual control of the reflection value

Hi all,
I would to control the reflection effect of a MirrorReflection shader…(controlling the reflections manually by value)…I want to use a white shader with reflection for my floor surface…like smooth and glossy floor…I don’t want a total reflection like a mirror and I don’t want to change the white color of the surface…this is the shader:

Shader "FX/Control Mirror Reflection" { 
Properties {
    _MainTex ("Base (RGB)", 2D) = "white" {}
    _ReflectionTex ("Reflection", 2D) = "white" { TexGen ObjectLinear }
    _Color ("Color Tint", Color) = (1,1,1,1)
}

// two texture cards: full thing
Subshader { 
	Color  [_Color]
    Pass {
        SetTexture[_MainTex] 
        { 
        	constantColor [_Color]
        	Combine texture * primary, texture * constant 
        }
        SetTexture[_ReflectionTex] { matrix [_ProjMatrix] combine texture * previous }
    }
}

// fallback: just main texture
Subshader {
    Pass {
        SetTexture [_MainTex] { combine texture }
 	   }
	}
}

like Jessy said…

I have added the _Color property but I have a problem with a multiply function …the shader doesn’t work as I want because I can’t reduce the reflection value by color (…or by slide)…the surface become dark if I change the white slot.
…suggestions?
thanks
bye

…this is the script on a surface:

using UnityEngine;
using System.Collections;

// This is in fact just the Water script from Pro Standard Assets,
// just with refraction stuff removed.

[ExecuteInEditMode] // Make mirror live-update even when not in play mode
public class MirrorReflection : MonoBehaviour
{
    public bool m_DisablePixelLights = true;
    public int m_TextureSize = 256;
    public float m_ClipPlaneOffset = 0.07f;
    
    public LayerMask m_ReflectLayers = -1;
        
    private Hashtable m_ReflectionCameras = new Hashtable(); // Camera -> Camera table
    
    private RenderTexture m_ReflectionTexture = null;
    private int m_OldReflectionTextureSize = 0;
    
    private static bool s_InsideRendering = false;

    // This is called when it's known that the object will be rendered by some
    // camera. We render reflections and do other updates here.
    // Because the script executes in edit mode, reflections for the scene view
    // camera will just work!
    public void OnWillRenderObject()
    {
        if( !enabled || !renderer || !renderer.sharedMaterial || !renderer.enabled )
            return;
            
        Camera cam = Camera.current;
        if( !cam )
            return;
    
        // Safeguard from recursive reflections.        
        if( s_InsideRendering )
            return;
        s_InsideRendering = true;
        
        Camera reflectionCamera;
        CreateMirrorObjects( cam, out reflectionCamera );
        
        // find out the reflection plane: position and normal in world space
        Vector3 pos = transform.position;
        Vector3 normal = transform.up;
        
        // Optionally disable pixel lights for reflection
        int oldPixelLightCount = QualitySettings.pixelLightCount;
        if( m_DisablePixelLights )
            QualitySettings.pixelLightCount = 0;
        
        UpdateCameraModes( cam, reflectionCamera );
        
        // Render reflection
        // Reflect camera around reflection plane
        float d = -Vector3.Dot (normal, pos) - m_ClipPlaneOffset;
        Vector4 reflectionPlane = new Vector4 (normal.x, normal.y, normal.z, d);
    
        Matrix4x4 reflection = Matrix4x4.zero;
        CalculateReflectionMatrix (ref reflection, reflectionPlane);
        Vector3 oldpos = cam.transform.position;
        Vector3 newpos = reflection.MultiplyPoint( oldpos );
        reflectionCamera.worldToCameraMatrix = cam.worldToCameraMatrix * reflection;
    
        // Setup oblique projection matrix so that near plane is our reflection
        // plane. This way we clip everything below/above it for free.
        Vector4 clipPlane = CameraSpacePlane( reflectionCamera, pos, normal, 1.0f );
        Matrix4x4 projection = cam.projectionMatrix;
        CalculateObliqueMatrix (ref projection, clipPlane);
        reflectionCamera.projectionMatrix = projection;
        
        reflectionCamera.cullingMask = ~(1<<4)  m_ReflectLayers.value; // never render water layer
        reflectionCamera.targetTexture = m_ReflectionTexture;
        GL.SetRevertBackfacing (true);
        reflectionCamera.transform.position = newpos;
        Vector3 euler = cam.transform.eulerAngles;
        reflectionCamera.transform.eulerAngles = new Vector3(0, euler.y, euler.z);
        reflectionCamera.Render();
        reflectionCamera.transform.position = oldpos;
        GL.SetRevertBackfacing (false);
        Material[] materials = renderer.sharedMaterials;
        foreach( Material mat in materials ) {
            if( mat.HasProperty("_ReflectionTex") )
                mat.SetTexture( "_ReflectionTex", m_ReflectionTexture );
        }
        
        // Set matrix on the shader that transforms UVs from object space into screen
        // space. We want to just project reflection texture on screen.
        Matrix4x4 scaleOffset = Matrix4x4.TRS(
            new Vector3(0.5f,0.5f,0.5f), Quaternion.identity, new Vector3(0.5f,0.5f,0.5f) );
        Vector3 scale = transform.lossyScale;
        Matrix4x4 mtx = transform.localToWorldMatrix * Matrix4x4.Scale( new Vector3(1.0f/scale.x, 1.0f/scale.y, 1.0f/scale.z) );
        mtx = scaleOffset * cam.projectionMatrix * cam.worldToCameraMatrix * mtx;
        foreach( Material mat in materials ) {
            mat.SetMatrix( "_ProjMatrix", mtx );
        }
        
        // Restore pixel light count
        if( m_DisablePixelLights )
            QualitySettings.pixelLightCount = oldPixelLightCount;
        
        s_InsideRendering = false;
    }
    
    
    // Cleanup all the objects we possibly have created
    void OnDisable()
    {
        if( m_ReflectionTexture ) {
            DestroyImmediate( m_ReflectionTexture );
            m_ReflectionTexture = null;
        }
        foreach( DictionaryEntry kvp in m_ReflectionCameras )
            DestroyImmediate( ((Camera)kvp.Value).gameObject );
        m_ReflectionCameras.Clear();
    }
    
    
    private void UpdateCameraModes( Camera src, Camera dest )
    {
        if( dest == null )
            return;
        // set camera to clear the same way as current camera
        dest.clearFlags = src.clearFlags;
        dest.backgroundColor = src.backgroundColor;        
        if( src.clearFlags == CameraClearFlags.Skybox )
        {
            Skybox sky = src.GetComponent(typeof(Skybox)) as Skybox;
            Skybox mysky = dest.GetComponent(typeof(Skybox)) as Skybox;
            if( !sky || !sky.material )
            {
                mysky.enabled = false;
            }
            else
            {
                mysky.enabled = true;
                mysky.material = sky.material;
            }
        }
        // update other values to match current camera.
        // even if we are supplying custom camera&projection matrices,
        // some of values are used elsewhere (e.g. skybox uses far plane)
        dest.farClipPlane = src.farClipPlane;
        dest.nearClipPlane = src.nearClipPlane;
        dest.orthographic = src.orthographic;
        dest.fieldOfView = src.fieldOfView;
        dest.aspect = src.aspect;
        dest.orthographicSize = src.orthographicSize;
    }
    
    // On-demand create any objects we need
    private void CreateMirrorObjects( Camera currentCamera, out Camera reflectionCamera )
    {
        reflectionCamera = null;
        
        // Reflection render texture
        if( !m_ReflectionTexture || m_OldReflectionTextureSize != m_TextureSize )
        {
            if( m_ReflectionTexture )
                DestroyImmediate( m_ReflectionTexture );
            m_ReflectionTexture = new RenderTexture( m_TextureSize, m_TextureSize, 16 );
            m_ReflectionTexture.name = "__MirrorReflection" + GetInstanceID();
            m_ReflectionTexture.isPowerOfTwo = true;
            m_ReflectionTexture.hideFlags = HideFlags.DontSave;
            m_OldReflectionTextureSize = m_TextureSize;
        }
        
        // Camera for reflection
        reflectionCamera = m_ReflectionCameras[currentCamera] as Camera;
        if( !reflectionCamera ) // catch both not-in-dictionary and in-dictionary-but-deleted-GO
        {
            GameObject go = new GameObject( "Mirror Refl Camera id" + GetInstanceID() + " for " + currentCamera.GetInstanceID(), typeof(Camera), typeof(Skybox) );
            reflectionCamera = go.camera;
            reflectionCamera.enabled = false;
            reflectionCamera.transform.position = transform.position;
            reflectionCamera.transform.rotation = transform.rotation;
            reflectionCamera.gameObject.AddComponent("FlareLayer");
            go.hideFlags = HideFlags.HideAndDontSave;
            m_ReflectionCameras[currentCamera] = reflectionCamera;
        }        
    }
    
    // Extended sign: returns -1, 0 or 1 based on sign of a
    private static float sgn(float a)
    {
        if (a > 0.0f) return 1.0f;
        if (a < 0.0f) return -1.0f;
        return 0.0f;
    }
    
    // Given position/normal of the plane, calculates plane in camera space.
    private Vector4 CameraSpacePlane (Camera cam, Vector3 pos, Vector3 normal, float sideSign)
    {
        Vector3 offsetPos = pos + normal * m_ClipPlaneOffset;
        Matrix4x4 m = cam.worldToCameraMatrix;
        Vector3 cpos = m.MultiplyPoint( offsetPos );
        Vector3 cnormal = m.MultiplyVector( normal ).normalized * sideSign;
        return new Vector4( cnormal.x, cnormal.y, cnormal.z, -Vector3.Dot(cpos,cnormal) );
    }

…continue previous code

    // Adjusts the given projection matrix so that near plane is the given clipPlane
    // clipPlane is given in camera space. See article in Game Programming Gems 5.
    private static void CalculateObliqueMatrix (ref Matrix4x4 projection, Vector4 clipPlane)
    {
        Vector4 q = projection.inverse * new Vector4(
            sgn(clipPlane.x),
            sgn(clipPlane.y),
            1.0f,
            1.0f
        );
        Vector4 c = clipPlane * (2.0F / (Vector4.Dot (clipPlane, q)));
        // third row = clip plane - fourth row
        projection[2] = c.x - projection[3];
        projection[6] = c.y - projection[7];
        projection[10] = c.z - projection[11];
        projection[14] = c.w - projection[15];
    }

    // Calculates reflection matrix around the given plane
    private static void CalculateReflectionMatrix (ref Matrix4x4 reflectionMat, Vector4 plane)
    {
        reflectionMat.m00 = (1F - 2F*plane[0]*plane[0]);
        reflectionMat.m01 = (   - 2F*plane[0]*plane[1]);
        reflectionMat.m02 = (   - 2F*plane[0]*plane[2]);
        reflectionMat.m03 = (   - 2F*plane[3]*plane[0]);

        reflectionMat.m10 = (   - 2F*plane[1]*plane[0]);
        reflectionMat.m11 = (1F - 2F*plane[1]*plane[1]);
        reflectionMat.m12 = (   - 2F*plane[1]*plane[2]);
        reflectionMat.m13 = (   - 2F*plane[3]*plane[1]);
    
        reflectionMat.m20 = (   - 2F*plane[2]*plane[0]);
        reflectionMat.m21 = (   - 2F*plane[2]*plane[1]);
        reflectionMat.m22 = (1F - 2F*plane[2]*plane[2]);
        reflectionMat.m23 = (   - 2F*plane[3]*plane[2]);

        reflectionMat.m30 = 0F;
        reflectionMat.m31 = 0F;
        reflectionMat.m32 = 0F;
        reflectionMat.m33 = 1F;
    }
}

http://answers.unity3d.com/questions/8029/how-can-i-control-the-strength-of-the-reflection-in-the-pro-fx-water-shader

This is code for allowing you to change the reflect value of the water shader, which is pretty much the same thing. However, apparantly it won’t work on a PC, only a Mac. If anyone has the solution for this please share!

Actually, I just figured out a way of adjusting the reflection value by creating your own Fresnel Texture. Here’s a link to the page where I describe it.

http://answers.unity3d.com/questions/8029/how-can-i-control-the-strength-of-the-reflection-in-the-pro-fx-water-shader/55992#55992

Your approach is kind of clumsy: it reduces the built-in fresnel effect to a single-colour input.

In what way does the first answer not work on PCs?

color.rgb = lerp( water.rgb, refl.rgb, _ReflectionStrength );

I did this exact same thing on my water shader, and it worked just fine on my windows machine.

Yes it does, my approach was actually intended more for glass than water. The built in fresnel effect changes the reflection value based on the viewing angle, which looks unrealistic in glass. My approach makes the entire plain have the same reflect value dependent on the opacity of the texture.

I have a PC, and I followed that previous link’s instructions perfectly, but it didn’t work. One thing I found odd was his answer requested you to change the line “#ifdef WATER_REFRACTIVE” and another like it. However, the water code has “#if define WATER_REFRACTIVE” or something similar, I don’t have the code at the moment. I’ve tried both combinations and neither works.

This person is having the same problem. http://answers.unity3d.com/questions/50877/problem-reducing-reflections-in-water-shader-on-pc