General Category > Ongoing Anim8or Development
Changed to Older Releases [builds 1162 to 1230]
Trevor:
"You're using class=glossyreflector but haven't specified the other material properties. The value of the attribute Kr is important. (If you didn't add it then Anim8or uses the specular factor Ks in its place). The higher this value is the more energy will be reflected, but it will also mask the basic color of the underlying materisl. Also if you set the roughness very high it will make the surface more mirror-like."
Ah yes, thats correct, I only set glossyreflector and used Specular for Reflection intensity (0.99 - almost entirly reflected. at >1 the scene truns black since I assume it reflects all the rays and never back toward the camera)
And yes, Roughness is 10. at 1 there wasnt enough of a bright patch but > 10 causes too much image reflection (polished mirror, which is not what I want, I want 'diffuse Inter-reflection')
Yeah, while the light is far away, with the bright patch overloaded to burnout, this should be anough to reflect more rays.
The patch on the wall is actually looking directly at a sun type light, so its receiving 100% light already anyhow.
"It uses rather extreme lighting, with extreme contrast. Only a tiny percent of light that enters will reach the far corners of the room. Almost all rays are absorbed before they make the multiple bounces off of the room on their way. They dynamic range of light values far exceeds what a normal computer monitor can display."
Erm, yes, the only way to test Diffuse Inter-reflection is to look down a corridor with only 1 diffuse light source, i.e. A Primary light source that is bounced off a primary wall to make a secondary (diffuse/reflected) light source.
As for the contrast, theres nothing I can do about that, thats ARTs desision.
Also, as can be seen, the Secondary Light source has a value of 1.0(255), this should be = to adding a local light of 255 at every point (although this is where calculations get dificult) and then bouncing that ray to the next surface. That secondary wall will be lit by 1/(distance^2) power light
"but it will also mask the basic color of the underlying materisl."
Yes, if Specular is set to colour only then it doesnt show any texture, I copied the texture to specular and now it shows the texture.
Would this not be nessesary if I re-set specular to 0 and then used Kr?
Ill test it
Trev
Ok, tested using Kr. Kr is better than Specular as it doesnt add an untextured layer over the base (causing all reflections to appear just grey) so no longer a requirement to assign a texture to Specular.
However, Kr is still limited to <1.
I have just done another render and this time Ive used 0.5 and it looks the same as the one posted above (will post once render complete)
It seems that as you increase Kr, the darker the surface becomes. At 0.5, as much light is reflected as is refracted.
My lighting is still at 10 though (equivelant to adding 10 suns (infinit lights))
Also, I dissabled Ambiant Occlusion, hehe, whats the point in having it on when this replaces it more accuriatly :P
Taking a real scenario of this render (Bright sunlit door and no lights on inside), the Diffuse Inter-reflection is definatly more intense than ART is achiving.
Init=0.54, render=3399.69, rays=63307553
I made a composit of an extremem render to get an aproximitly better result, still not perfect though.
Steve:
--- Quote ---Kr is still limited to <1.
--- End quote ---
It makes no sense to make is greater than one - that would cause the amount of light energy in a scene to increase each time a ray hit something. The total amount of light energy in a scene is the sum of the energy in all the lights, nothing more. When light hit a surface part of that energy is absorbed and part is reflected, depending on the particular properties of the material.
As I've said, your scene has a very high contrast ratio because the percentage of energy (per area) that reached the back wall is a tiny fraction of what strikes the brightest parts. A normal computer screen can only show a portion of the range of energies present in this scene.
There are "high dynamic range" (HDR) techniques that compress this contrast into a more visually (to many people) image but Anim8or doesn't currently support this.
Trevor:
"It makes no sense to make is greater than one "
Quite true, I just thought Id test and mention it.
To have a reflected ray increase in intensity would be silly, but I tested to see if there could be a way to brighten the image, obviously any value after 1 causes the scene to be black.
"There are "high dynamic range" (HDR) techniques that compress this contrast into a more visually (to many people) image but Anim8or doesn't currently support this."
Ah, Prahaps this is what I see in other renderers. I mean, I understand that a monitor is limited to 0-255 and that our vision is way, wayyy higher than that.
I guess this has become the norm for me when rendering Kitchens in Compusoft Winner.
To digress slightly Winner renders scenes similarly to Blender in that its like Old web pages. It first shows 16x16 pixles over the screen and progressivly subdivides these pixles.
Unlike Blender it has a 2 pass method.
It first uses something called a GI estimator before Raytracing.
In the previous post I said Id post a real scenario of the rendered scene.
Here (2015_03_10_23_16_22.jpg) I used the Kitchen light and no other light was on.
I concede that the far end of the hall which is much closer than in the scene is pretty dark, however the biggest difference is in the near field brightness.
The Secondary Light source is on the left wall. This causes the wall on the right to appear quite bright and as such causes a tertiary light source.
This propagates down the hall and the door frames are quite visible.
Most of the light seen is mostly secondary and tertiary with any 4th and 5th being noticable only in shadows and on the backside of the doorframes (hidden from view)
Anyway, Im sure you are very well aware of lighting and the mathematics of it. Im merly pointing out that photographs seem to differ from renders.
It might be that using glossyreflector is not going to work and that another method is required.
I just assumed that glossyreflector should work since its the same technique, bounce rays round.
Trev
P.S. the other 2 images use the hallway light.
2015_03_10_23_01_39.jpg again shows secondary ant tertiary light.
2015_03_10_23_04_37.jpg shows 4th light which is almost non existant on camera, even though the human eye can see fine.
I made this with AA set to 1024. It took a few hours, I forgto to record the number of rays.
polyGon_tError:
hello Steve,
i was unable to use Anim8or in my company PC (where i am working now mostly), having intel G41 chip, Windows7 64bit and built-in graphics. i was sad and stopped trying it after many failure (though 3D Max 2012 work very well in it)!
but recently i get graphics driver update from intel (directly from intel not of motherboard manufacturer!) and it is working like before! (my usual PC is of celeron with winxp/ winxp live/ windows server 2003! and it work well there)
do you use 'Silicon Graphics' spec of OpenGL or of major vendor (like S3) or that of intel? can't you make it more supported esp. to that of major vendor?
Steve:
The OpenGL spec is standard across all companies. There are multiple levels of OpenGL but Anim8or works with everything from 1.1 to the latest 4.5.
There are also a lot of vendor specific extensions but I don't use any. Unfortunately some vendors (he looks at Intel with a painful grimace) don't test their drivers very well before releasing them, and consequently they can be buggy. The best thing to do when there is a problem is to check for an updated driver.
You can query OpenGL drivers for what extensions they support. Anim8or always does this before using them.
I wish I could test Anim8or on all the thousands of different versions of chips, OSs, drivers, etc., but that's simply not possible. I do have some things built into Anim8or to help locate certain issues which has helped me find workarounds in the past. For example, if you stare Anim8or with the command line argument -traceinit it will show it's progress as it's starting up.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version