POV-Ray : Newsgroups : povray.binaries.images : Normals have a directional bias : Re: Normals have a directional bias Server Time
15 Jul 2024 07:16:25 EDT (-0400)
  Re: Normals have a directional bias  
From: Hj  Malthaner
Date: 7 Jan 2021 17:12:59
Message: <5ff7876b$1@news.povray.org>
On 1/7/21 5:29 PM, William F Pokorny wrote:
> On 1/6/21 5:33 PM, Hj. Malthaner wrote:
>> What is the goal of Povr?


> - Initially, a simpler version of "POV-Ray" supporting the existing 
> scene language and the most common features while fixing as many 
> longstanding bugs (and broken features) as I can.

That's something I like. A simpler codebase is easier to understand, and 
maintain. Also should makes finding bugs easier.

>> I've noticed a bug with media effects behind semi-transparent image 
>> maps on transparent objects. Not entirely sure if it's really a bug or 
>> if my combination of glass sheets and "holographic" displays was ...
> If you believe there's a bug in the current official release, the usual 
> place starting post would be povray.bugreports. Or, povray.beta-test, if 
> it a problem particular to v3.8 development. Either probably works out 
> and cutting the issue down to as simple a scene as possible a great help.

I'll do so once I have set up a scene file to reproduce the problem in a 
simple way ... or found out that I was stupid somewhere and the fault is 
mine. Right now It's too early to make an official report here.

>> https://en.wikipedia.org/wiki/Path_tracing
> I never know what to do with pointers to the latest and greatest - 
> whatever.

20 years is not so new, but yes ... the only reason to post was cause 
the Cycles renderer uses this and produces very good quality. I just 
wanted to make sure we both have the same state of knowledge.

>> I think this feature is what makes the Cycles renderer produce better 
>> images than PovRay with radiosity. 
> Somewhat agree. One place where I believe POV-Ray comes up short is in 
> handling finish highlights where radiosity, area lights and ??? are in 
> play.
> While I mostly kept a distance from the finish changes Christoph was 
> working on for v3.8(1), I believe the aim for many of the changes - like 
> always specifying an interior ior - was to better handle surface 
> finishes (highlights especially) in a real world way. Expect others here 
> know better than me the extent to which my belief is true?

I must admit I know nothing about these changes, even that I use a 3.8 
alpha version.

> I think mostly these v3.8 finish block changes haven't been exploited to 
> date. If they more often were, would the highlight differences compared 
> to Cycles (et al) be as dramatic? I don't know for certain, but I 
> suspect less so.

For sure I have not, cause I didn't even know about them. I'm still 
using what is documented for 3.6/3.7

I'll try to find some documentation about the finish related changes in 3.8

> At some point what's seen as best or better - what becomes common - is 
> just where the crowd of users ends up / happens to be. There is value in 
> following; It's easier to grab detailed work of others in terms of code, 
> models, materials, maps and such and stick it into your larger scene (or 
> program or whatever). Further, it's more likely the things you grab work 
> - at least in the main.

I agree. But while many change to Blender, this is why I asked how I can 
help. I'd hate to see PovRay die. It's been around so long and was one 
of the best free 3D programs for many years.

Since the last message I have been reading some parts of the code. The 
tracer core, texture handling, patterns, media. At the moment I think I 
could make some changes to patterns with some level of success. Some 
parts of the code, even in the patterns are very sophisticated (the 
algorithms, the code is still clean to read), and I don't think I could 
fix a problem there.

Now that you pointed me to the finish changes, I'll take a look into 
that next.

> Bill P.


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