Hi, We're currently looking to switch to ASTC, though I do have some queries regarding the graphics pipeline for HDR formats.
Since we're looking to retain image quality as much as possible, can we use an Exr format for rendering (We currently use this for creating out lightmaps), and convert them directly to ASTC for our build?
It just when I've loaded exr files in to Mali it appears to compromise the image data (Darkening down), I presume it's clamping the channels?
Is there a recommended pipeline for converting HDR images to ASTC that won't compromise the data?
Cheers,
Caroline
I am not sure how to view any attachments you provided - I'll follow up with our web team to see if it is possible via forum comments. I am still not sure how you are verifying the darkening; is this just visual output on the Mali Texture Compression Tool screen? Is the actual data in the texture itself too dark when viewed on an actual Mali GPU? The Mali Texture Compression Tool GUI is outputting to an LDR rendered output, so there needs to be some color transform when display the results (either dynamically rescaling the HDR value to fit into the 0 - 1 LDR range, or clipping). This is totally orthogonal to the data which ends up in the actual ASTC texture on disk.
Hi Peter,
Yes I wanted to send you the original file so you take a look at it in more detail, I've just tried to reattach (See image below), It looks as though I can't send you the original OpenExr file as this blog doesn't seem to recognize that file format? Though you can see it in the example below; test file just show a very basic 'Render To Texture' setup using OpenExr for light mapping.
Ideally we would like to be able to view HDR files within the Mali Texture Compression Tool and be able to view the before and after compression, so we can evaluate what optimal compression settings would be suitable for our work. But you seem to indicating that it Mali can not handle HDR files without altering and compromising the values, is that the case?
Thanks,