• Products
  • Solutions
  • Made with Unity
  • Learning
  • Support & Services
  • Community
  • Asset Store
  • Get Unity

UNITY ACCOUNT

You need a Unity Account to shop in the Online and Asset Stores, participate in the Unity Community and manage your license portfolio. Login Create account
  • Blog
  • Forums
  • Answers
  • Evangelists
  • User Groups
  • Beta Program
  • Advisory Panel

Navigation

  • Home
  • Products
  • Solutions
  • Made with Unity
  • Learning
  • Support & Services
  • Community
    • Blog
    • Forums
    • Answers
    • Evangelists
    • User Groups
    • Beta Program
    • Advisory Panel

Unity account

You need a Unity Account to shop in the Online and Asset Stores, participate in the Unity Community and manage your license portfolio. Login Create account

Language

  • Chinese
  • Spanish
  • Japanese
  • Korean
  • Portuguese
  • Ask a question
  • Spaces
    • Default
    • Help Room
    • META
    • Moderators
    • Topics
    • Questions
    • Users
    • Badges
  • Home /
avatar image
0
Question by Mogrinnar · Mar 02, 2015 at 02:08 AM · shaderscg

Having trouble with The Cg Tutorial book's exercises in Unity.

I am trying to get a good grasp on shaders so I started to read the The Cg Tutorial.

I am trying to do the 4th exercise of the 3rd chapter, the C3E4v_twist Vertex Program (scroll down two thirds).

I have adapted the code in the book to run in Unity3D 4.5.5f1. This is what it looks like.

 Shader "Custom/Tesselation" 
 {
  Properties {
          twistValue ("twistValue", Float) = 0
  }
 
     SubShader 
     {
         Pass 
         {
             CGPROGRAM
             #pragma vertex C3E4v_twist
             #pragma fragment frag
             #pragma target 3.0
 
             #include "UnityCG.cginc"
             
             uniform float twistValue;
             
             struct C3E4_Output
             {
                 float4 position : POSITION;
                 float4 output_color    : COLOR;
             };
         
             C3E4_Output    C3E4v_twist(float4 position : POSITION, float4 in_color: COLOR)
             {
                 C3E4_Output OUT;
 
                 float angle = twistValue * length(position);
 
                 float cosLength, sinLength;
 
                 sincos(angle, sinLength, cosLength);
                 
                 float4 newPos;
 
                 newPos[0] = cosLength * position[0] +
 
                    -sinLength * position[1];
 
                 newPos[1] = sinLength * position[0] +
 
                     cosLength * position[1];
 
                 newPos[2] = 0;
 
                 newPos[3] = 1;
                 
                 OUT.position = mul(UNITY_MATRIX_MVP, newPos);
 
                 OUT.output_color = in_color;
 
                 return OUT;
             }
             
             fixed4 frag() : COLOR 
             {
                 return fixed4(1.0,0.1,0.1,1.0);
             }
             ENDCG
         }
     }
 }

Here is what it looks like. The plane does a 90 degrees on the X-Axis and twists from the center of the plane, whereas it twists from the extremities in the book.

Does anyone have an idea of what I am doing wrong ?

Comment
Add comment
10 |3000 characters needed characters left characters exceeded
▼
  • Viewable by all users
  • Viewable by moderators
  • Viewable by moderators and the original poster
  • Advanced visibility
Viewable by all users

0 Replies

· Add your reply
  • Sort: 

Your answer

Hint: You can notify a user about this post by typing @username

Up to 2 attachments (including images) can be used with a maximum of 524.3 kB each and 1.0 MB total.

Welcome to Unity Answers

If you’re new to Unity Answers, please check our User Guide to help you navigate through our website and refer to our FAQ for more information.

Before posting, make sure to check out our Knowledge Base for commonly asked Unity questions.

Check our Moderator Guidelines if you’re a new moderator and want to work together in an effort to improve Unity Answers and support our users.

Follow this Question

Answers Answers and Comments

20 People are following this question.

avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image

Related Questions

Using Vertex Color increases Draw Call 0 Answers

How to get camera location in object space? 1 Answer

Learning shaders for unity4 1 Answer

Shader Help? Need an Alpha Test, then a "set pixel" sort of command 1 Answer

General question about shading in unity 2 Answers


Enterprise
Social Q&A

Social
Subscribe on YouTube social-youtube Follow on LinkedIn social-linkedin Follow on Twitter social-twitter Follow on Facebook social-facebook Follow on Instagram social-instagram

Footer

  • Purchase
    • Products
    • Subscription
    • Asset Store
    • Unity Gear
    • Resellers
  • Education
    • Students
    • Educators
    • Certification
    • Learn
    • Center of Excellence
  • Download
    • Unity
    • Beta Program
  • Unity Labs
    • Labs
    • Publications
  • Resources
    • Learn platform
    • Community
    • Documentation
    • Unity QA
    • FAQ
    • Services Status
    • Connect
  • About Unity
    • About Us
    • Blog
    • Events
    • Careers
    • Contact
    • Press
    • Partners
    • Affiliates
    • Security
Copyright © 2020 Unity Technologies
  • Legal
  • Privacy Policy
  • Cookies
  • Do Not Sell My Personal Information
  • Cookies Settings
"Unity", Unity logos, and other Unity trademarks are trademarks or registered trademarks of Unity Technologies or its affiliates in the U.S. and elsewhere (more info here). Other names or brands are trademarks of their respective owners.
  • Anonymous
  • Sign in
  • Create
  • Ask a question
  • Spaces
  • Default
  • Help Room
  • META
  • Moderators
  • Explore
  • Topics
  • Questions
  • Users
  • Badges