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More tracing, now with refraction!

Posted: Tue Dec 16, 2003 4:09 pm
by ton
Hi,

http://www.blender.org/bf/monkey_glass.jpg
http://www.blender.org/bf/monkey_glass_fresnel.jpg

We are gathering testing binaries, and this monkey file here:
http://download.blender.org/demo/test/

Just committed. :-)

Here's the changelog: (real user docs come, please bear in mind that
this is unfinished, and for test only)

- enable refraction with button "Ray Transp" in Material buttons.
- set "Angular Index" value for amount of refraction. (will be "IOR")
- use the "Alpha" value to define transparency.
- remember to set a higher "Depth" too... glass can bounce quite some
more than expected.
- for correct refraction, 3D models MUST have normals pointing in the
right direction (consistently pointing outside).
- refraction 'sees' the thickness of glass based on what you model. So
make for realistic glass both sides of a surface.

- I needed to do some rewriting for correct mirroring/refraction,
especially to prevent specularity being blended away.
Solved this with localizing shading results in the rendercore.c.
Now specularity correctly is added, and reduces the 'mirror' value.
- Localizing more parts of the render code is being planned. The old
render heavily relies on struct Render and struct Osa to store globals.
For scanline render no problem, but recursive raytracing dislikes that.

- done test with gamma-corrected summation of colors during tracing, is
commented out still. But this will give more balanced reflections. Now
dark reflections that are reflected in a bright surface seem incorrect.

- Introduced 'Fresnel' effect for Mirror and Transparency. This
influences the amount of mirror/transparency based at viewing angle.
Next to a new Fresnel slider, also a 'falloff' button has been added to
define the way it spreads.
- Fresnel also works for Ztransp rendering

- created new Panel for Raytrace options
I have to evaluate still where it all should be logically located.
- material preview shows fake reflection and fake refraction as well.

Posted: Tue Dec 16, 2003 4:37 pm
by ada89
Ooh Ooh Ooh

Posted: Tue Dec 16, 2003 5:02 pm
by slikdigit
Awesome! thanks for the great work, Ton. :D
unfortunately I can't test this yet. Both Desktop and laptop have problems (RAM and CMOS) :(

Posted: Tue Dec 16, 2003 6:44 pm
by thorwil
Speed of development is incredible!
And many thanks for all the work and releasing previews.

But sadly trying to execute the Linux build results in a window flashing followed by the error message:
Illegal instruction

No such problem with the previous raytrace preview (where I was only to dumb to make it executeable right away)
Any ideas?

Posted: Tue Dec 16, 2003 6:59 pm
by ton
I've uploaded linux build again, it was apparantly compiled with optimizing for athlon...

Posted: Tue Dec 16, 2003 7:24 pm
by blendermax
this is great!! :D

on thing though; what about refraction?

oh, another question: is this yafray code?

Posted: Tue Dec 16, 2003 7:38 pm
by modron
I am not having much luck with the refraction so far, but it's there. Big thanks to all.

Posted: Tue Dec 16, 2003 7:38 pm
by kirpre
Ton, are you sleeping? It seems like something major has come out every other day. Thanks so much for all your hard work.

Posted: Tue Dec 16, 2003 7:56 pm
by ada89
Woaw, just test it and it work nicely(but i'm not sure if it accurate :wink: ) I think it is...is it?? :D

Now rendering with better scene....


note: thanks ztonzy for the compile

Posted: Tue Dec 16, 2003 8:07 pm
by thorwil
ton wrote:I've uploaded linux build again, it was apparantly compiled with optimizing for athlon...
Thanks, but I have an Athlon (not XP). Still the same problem. What else could it be besides processor optimization?

Maybe I will try to compile form CVS on the weekend.

Posted: Tue Dec 16, 2003 8:19 pm
by Hos
BTW: the 65000 verts per mesh limit has been removed
from this test version too ... please test that and report
any problems to the bug tracker.

Chris

Posted: Tue Dec 16, 2003 8:24 pm
by Eric
Ton, whatever pills your taking I think you should stop taking them. If you don't you'll be burnt out very soon! :D

Posted: Tue Dec 16, 2003 8:50 pm
by forcefield
Ton you are amazing!!

Windoze Bin anyone?

Posted: Tue Dec 16, 2003 8:53 pm
by ada89
Ztonzy threat in news and chat at Elysiun :D

Tested on FreeBSD 4.9-STABLE

Posted: Tue Dec 16, 2003 9:33 pm
by thornae
Building from cvs code, seems to work fine. However, when rendering the monkey test file as it is given, my image doesn't quite match those posted (glass seems lighter - see here for comparison with Ton's as posted above). This could be to do with settings for fresnel falloff or something similar - any chance of getting the settings used for the above images that differ from the given test file?

Also, the arrows for single digit adjusting of falloff settings don't seem to work - click and drag adjusting only - but this may be my not having fully read the new UI docs.

All in all - Ton rocks my world.

Incidentally, I've been bug-eyed by how much Blender's changed since I've been away from it, all for the better. It's looking like a bright blending future.