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Re: Simulate sun position and lights/shadows
db4tech and Hans, thank you for your tests.
notice the knobs on the unit and strangely the curtains?
The curtains use a flwhite material equal to:
Ka 0.6449 0.6116 0.5447 Kd 0.9837 0.9309 0.8392 Ks 0.8082 0.7290 0.5708 illum 2 Ns 200.0000
Therefore they are too shiny. Before Sweet Home 3D supported MTL files, the colors of 3D models were colors predefined in this document, and many contributors (including me) were choosing a color without taking into account its shininess and specular color defined with newmtl tags here. If we go forward with lights management, the shininess of all these old 3D models will have to be reviewed, but this is a tedious work that won't be done until we find the good parameters for the renderers and the shaders.
The window frame and probably the chair have the same problem. Maybe I should simply reduce shininess and specular color when I use them in SunFlow renderer.
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Emmanuel Puybaret, Sweet Home 3D creator
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Re: Simulate sun position and lights/shadows
fhoofman, Uber shader and Phong shader plug-ins are for test purpose only. I developed them quickly on the basis of the advanced rendering plug-in, and I'll probably delete them later. If the unstable state of these 2 plug-ins bothers you, please simply don't use or test them.
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Emmanuel Puybaret, Sweet Home 3D creator
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Re: Simulate sun position and lights/shadows
Update!
I have finally located the settings to achieve the floor style I want Yay!
At first I thought I had found them using the Phong shader but then it turns out that Phong is only able to produce this type of reflection, try getting a plain shiny floor without diffused reflections like Shiny shader when using Phong, even the shiniest surface is diffused!? So I experimented further and found the settings for Uber, Uber can produce surfaces with a matt finish, diffused reflection through to full glass like reflections.
I also found out that the nasty ceiling light scattering using Uber was caused the default Art of Illusion roughness setting (the Ns value being too low)
One strange thing though, the chair seat has no colour with Uber, could be as Emmanuel mentioned about some original objects being designed with unusual surface colour and values.
Oh and lights aren't rendering brighter with the new shaders, it is just that they are reflecting more.
Okay enough talk here are the results: First normal Advanced photo render (Shiny shader)
Then Phong While trying to produce a result like Shiny shader using Phong, this next image is the closest I can get??
Finally Uber (Perfect result)
Apart from some object textures that need fixing Uber produces the closest to the result I want and is the most versatile shader being able to produce dull, shinier or right through to (if required) a glass like surfaces.
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Re: Simulate sun position and lights/shadows
Thank you db4tech for your nice report. Uber shader seems to give nice results.
I'll have to see if I can use it instead of the shiny shader, but I'm not sure it will be part of the next release. The latest fixes in Beta 2.4 push me to release it very soon.
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Emmanuel Puybaret, Sweet Home 3D creator
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Re: Simulate sun position and lights/shadows
You're welcome!
Yes I have been carefully watching your Beta 2.4 thread with great interest but had to go back to using 2.3 to test the shaders and also so I could render my model with my extra lights and without the ceiling light.
Okay time for a further shader update.
I tried rendering one of the test models available on the Gallery page and found when using Uber (like the chair seat) the leaves render grey.
After some experimentation I think I now know why.
I could be wrong but I believe just a few tweaks are required to solve both problems. I found with my tree test (as with the curtains and some other surfaces in my room test) that the grey leaves are caused by their texture value being seen as too shiny, at the moment shiny textures values are being interpreted as off the scale so are then rendered grey instead (parts of the curtains where they become too shiny are also grey). Also the rough texture values are being interpreted as too rough which is what caused the extreme light scattering in my first few room render tests.
So rather than needing to edit every model the only thing that should need adjusting is how Uber interprets the presented shiny and rough texture values,
After finding the tree leaf solution I then tried editing the textures of the chair model to see if my above hypothesis was correct but sadly the chair model contains layered UV mapped textures, once I exported the model as an .obj from Art of Illusion with the shiny texture corrections, I was then unable to load the model into Sweet Home.
I suppose you are also going to want to know how I managed to get such nice looking grass!
db4tech
Further thoughts: Since Uber shader is a mix of a few shaders, is it possible that instead of the leaves and some other shiny surfaces being grey that their shiny value is being mistakenly interpreted to high so they are being rendered with a Mirror shader instead? Just trying to think of a solution to the phenomena.
Edit: to add further thoughts.
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[Edit 1 times,
last edit by db4tech at May 25, 2010, 1:21:57 AM]
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Re: Simulate sun position and lights/shadows
Hi Emmanuel,
I'm not sure if you have done any further work on the shaders since version 1.3 of advanced and Uber, so I will present some findings using version 1.3.
Could there be a memory leak with the shaders or SunFlow? I ask this because if I render the same scene (containing lots of textures) then change a few things to improve the scene, then re-render (I do this quite a lot tweaking things (400x300 fast setting)) at first the renders are very fast but then renders start to slow down, eventually the scene tries to render, thinks for a while and a red x shows. The only fix is to close Sweet Home then start Sweet Home again with the same scene, after this rendering is very fast for a while.
I have tried this with more than one model (for my course work) to be honest, when I am happy everything looks right and I am ready for a final render, I always close the Sweet Home program then open it because it renders my final scene faster.
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Re: Simulate sun position and lights/shadows
db3tech, Emmanuel:
DB, that's an interesting observation. I didn't test it as methodically as you did, but it rings a bell. I sometimes get "half" renders, where the rendering stops halfway the picture. Also, when rendering this picture in high quality (size 400x300 pixels) it took AGES (as in "several hours") to complete. Maybe that was because I used around 25 lights, but the rest of the scene was very simple: just the lady and the tree (OK, that's a complex model) and a wall with a small texture.
If I have more time, I will certainly try to do some more testing in the next days.
Hans
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Hans
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Re: Simulate sun position and lights/shadows
Hi Hans,
Thanks for your feedback. Yes I have experienced half (or unfinished) renders too when the render engine either thinks it has finished or runs out of buffer space? It doesn't happen very often but once it has happened the only solution (as mentioned in my previous post) is to close and reopen Sweet Home, then all is well (unless lots more renders are carried out)
Hope you are having a nice weekend. db4tech
PS: Yes I spotted the render of your lady friend Emmanuel's comment made me smile.
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Re: Simulate sun position and lights/shadows
Could there be a memory leak with the shaders or SunFlow?
Thank you db4tech for giving details how to reproduce this bug. You were on the right track because the problem comes from textures management in SunFlow. I just discovered it uses internally some kind of cache for the textures which is never reset. Too bad we discover this problem after the version 2.4 release. There's a dirty fix that I can program in the next release of the plug-in. I'll see if I do it or not.
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Emmanuel Puybaret, Sweet Home 3D creator
