PDA

View Full Version : Beginning OpenGL User's Compressonator Question



larryl
01-04-2017, 03:18 AM
Hi Folks:

I'm a new member of this forum, and I seem to be restricted to what links and images I can post.

Attempts to upload PNG and JPG images created by Windows Paint pop up a window with "<File name>: This is not a valid image file":

The following link to a screenshot captured with gyazo doesn't show up in preview:

https://gyazo.com/08d994783daa86a2e36f9f85e906bcc0

I'm attempting a post to see what happens.

Yea, that gyazo link didn't work either.

Can I have a moderator take a look at a post and get it in here?

Does anybody know of a Compressonator forum?

Thanks
Larry

Dark Photon
01-04-2017, 05:27 AM
New users can't post web links (spam prevention). Just post the URL without the leading http:// or https://. We'll fix up the link for you after you post.

larryl
01-04-2017, 02:36 PM
Hi Folks:

I'd like to learn use OpenGL. I'd like my first project to render and manipulate a model I've built with Blender in my C++ application.

This (http://www.opengl-tutorial.org/) OpenGL tutorial looks promising, Blender is mentioned in some lessons I've gone through. Any other Blender oriented OpenGL tutorials I should look at?

The lesson I'm hung up on right now deals with applying textures. It concludes with a recommendation to use Compressonator.

A search for "Compressonator" suggests that is a valid topic for this forum so here goes...

I'm running Compressonator version 2.4.3213.0.

On this (http://www.opengl-tutorial.org/beginners-tutorials/tutorial-5-a-textured-cube/) page, about 3/4 down, the tutorial suggests this method to select compression to DXT1, DXT3 or DXT5:

https://i.gyazo.com/08d994783daa86a2e36f9f85e906bcc0.gif

https://i.gyazo.com/08d994783daa86a2e36f9f85e906bcc0.gif

Ok, got it. So I fire up Compressonator but I don't see anything offering up a choice of DXT formats. I've selected a BMP file and clicked buttons all over Compressonator's window.

When I try to run the "Getting Started" exercise from Compressonator's help I was unable to bring up the Compressonator menu I saw in the tutorial:

https://i.gyazo.com/38ccc41bc700ed60382ffddae7e80739.gif

https://i.gyazo.com/38ccc41bc700ed60382ffddae7e80739.gif

Where the text above the Compressonator screenshot in the tutorial tells me to "Generate mipmaps", all I can get to is that little "Generate MIP Maps" window asking me to select a "Lowest Mip-level". How do I see the selection of texture formats in the tutorial's screenshot?

What am I doing wrong?

Thanks
Larry

paul_g_griffiths
01-04-2017, 02:58 PM
https://learnopengl.com/ a superior site.

Thought you should know, DXT is a directX format. Not openGL.

larryl
01-04-2017, 04:34 PM
https://learnopengl.com/ a superior site.

Thought you should know, DXT is a directX format. Not openGL.

Thanks Paul:

That tutorial looks good, the model section mentions Blender.

I'd like to pursue this course for a little bit.

I won't pretend to understand how this is supposed to work. It looks like a BMP file is fed to Compressonator, which uses the DXT format in the compression, but then exports a DDS file for consumption by the OpenGL code.

Is Compressonator a commonly used tool for working with textures?

I'm curious why Compressonator isn't providing the menus I see in the tutorial's Compressonator screen shots.

Thanks
Larry

Dark Photon
01-05-2017, 06:38 AM
Thought you should know, DXT is a directX format. Not openGL.

DXT compression formats have long been available in OpenGL.

https://www.khronos.org/opengl/wiki/S3_Texture_Compression