[x]
Posted via EE Mobile

Search, ask, and monitor your questions on the go with EE Mobile. Visit Experts Exchange from your mobile device and never be out of touch again.

Question
[x]
Attachment Details
[x]
The Solution Rating System

With so many solutions, how can you tell which solutions are most likely to help you and which ones are not? To provide you with a tool to use, we rate our solutions based on various elements that most accurately determine if a solution is a quality solution. To explain what factors affect the solution rating, here are the elements we take into consideration when formulating our solution rating.

  • The Grade of the Solution
  • The Zone Rank of the Expert Providing the Solution
  • The Number of Author and Expert Comments
  • The Number of Experts Contributing
  • The Feedback of the Community

Your Input Matters
Because of the way the system is set up, the most important variable in this equation is you. As a member of Experts Exchange, you are able to cast your vote on the quality of the solutions in regard to how complete, accurate, helpful and easy to understand each solution is. When you provide your feedback, each rating is adjusted accordingly. So, if you see a solution that has a poor rating that you think is a good solution, let us know by rating it. As you do, the rating will be adjusted and will become more accurate for other members of our site.

If you have any suggestions that you would like to make for our rating system, please ask a question in the Suggestions Zone of Community Support.

Thank you!

9.3

Rotating vertices/textures in vertex array/vbo

Asked by collages in OpenGL Graphics & Game Programming, C Programming Language

Tags: opengl es, rotation, vertice, texture, vbo, vertex buffer array

I'm fairly new to opengl (currently working with opengl es 1.1), and roughly understand how vertex arrays and vertex buffer arrays work.  However, I'm struggling to understand combining these structures with rotations/translations.  I know that I can run glTranslate and glRotate, but won't this affect everything in my array/buffer?  I've created an array of texture mapped vertices (to draw 4 textures on the screen at different positions), but how can I perform unique rotations/translations on each individual object if they all reside in the array/buffer ?

I'm trying to write the code as optimized as I can get it.  It works if I call glDrawArrays per each object on the screen, and rotate/translate each one individually in a glPopMatrix/glPushMatrix scenario, but isn't this in-efficient?  I read that ideally, all drawing operations should be done once.

Any advice?
 
 
[+][-]10/28/09 10:28 AM, ID: 25685885Accepted Solution

View this solution now by starting your 30-day free trial. Setting up your free trial is quick, easy, and secure. We will return you to this solution, unlocked, when you're done.

About this solution

Zones: OpenGL Graphics & Game Programming, C Programming Language
Tags: opengl es, rotation, vertice, texture, vbo, vertex buffer array
Sign Up Now!
Solution Provided By: ikework
Participating Experts: 1
Solution Grade: A
 
[+][-]10/28/09 01:48 PM, ID: 25688166Expert Comment

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
 
Loading Advertisement...
20091111-EE-VQP-89 - Hierarchy / EE_QW_3_20080625