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#311709
Regarding #4) are you using Transmittance at all? If your objects are solid, they should be a minimum of nd 3.0 (default). If you want to reduce the reflectivity of an object, the first place to do it is with lower Reflectance, not nd. However, since you notice that raising reflectance all the way up (255,255,255) still leads to dim reflections, you need to boost nd to increase that. But if your goal is less reflectivity, I'd begin with lower reflectance versus nd.


_Mike
#311734
(from the Japanese)
Thank you very much indeed, for your comment.
Because I said "I like this scene" in the previous message, I thought there would no more comment given to this topic.
It's wonderful.

Regarding #4), I am not using Transmittance at all. In the past, I had been using Transmittance for clipmap of blossom shape, but because now I have started using Layer box for clipmap as below, I just leave Transmittance untouched.
Image

And, as to the reflectivity of object, because my goal is to minimize the reflection of green color from the grassland on the surface of cherry blossom, I thought it was necessary to reduce reflectivity as much as possible.
And because I am using the texture of blossom both on reflectance 0 and reflectance 90 ( I made the texture on reflectance 90 a little brighter than that on refl 0),
I reduced Nd to 1.1.

And as to the solidness of object, well, I think I should not try to make the blossom transparent. (Instead, I should challenge to thinSSSS but that is still formidable...)

But I am now thinking if roughness is quite high like 95, then there will be no meaning in setting the value of Nd...
I am beginning to think, only when roughness is low, the value of Nd becomes meaningful because it determines how clearly the material reflects the surroundings...

And so I made a simple test as below.
The left ball is Nd1.1
The center ball is Nd3.0
The right ball is Nd40
All of the 3 balls have the same parameter as : Reflectance 0 color is R240G240B240, Reflectance90 color is R255G255B255, roughness 95.
And the result is as below:
Image
The result shows when Roughness is quite high, the same amount of green color appears on the surface of all the white balls, no matter how much Nd is.

And then I reduced roughness to 5, with all other parameters kept same and then I can see difference in how clearly the material reflects the surroundings.
And the result is below:
Image

The reason why the left ball looks dark is because, in my idea, the original color white cannot show up because roughness is low and, the surroundings are not clearly (or maybe I should say "brightly") reflected on the ball's surface because Nd is low too, thus, eventually the appearance of the left ball has to be dark.

So, after all, Nd probably has no influence over how much green light will be on the surface of cherry blossom, so long as I set a high value to Roughness.

Hmm...
User avatar
By tom
#311746
Koji, pause the project. It's not coming good, no offense. :)

Now, temporarily do these changes to achieve the goal:

Debugging...
1) Hide trees and blossoms etc. leave only the ground and physical sky.
2) Temporarily apply a medium grey lambert to the ground.
3) Make a floating plane on the ground and map the following texture on it >> /Maxwell 2/material database/textures/chart.png
4) Set ISO 100, Burn 0.8, Gamma 2.2
5) Hit render and adjust camera shutter until the colors look exactly like in the given texture.

You should be seeing something like this...
Please post it here and I will continue ;)

Image
#311980
(from the Japanese)
Thanks really, but, a strange thing happened in the scene.
Image

I put a plane with a texture of the chart, and one ball into my scene.
I can somehow see a part of sky even on the lower surface of the ball. I don't know why.

Then I erased "up and down" on the ground as below but still the reflection on the ball looks quite strange...
Image

???

But I found the above is because the motion blur was ON (I don't know why motion blur takes a role here), and so I re-rendered without motion blur and the result is OK as below.
Image

The material setting of the ball is R240 G240 G240, Nd 40, Roughness 0.
And the Shutter Speed 1/1000.
User avatar
By tom
#311989
OK, another motion blur bug. Could you send me the mblur scene? (tom@nextlimit.com)

Yes, now keep these settings (leave the chart around) and bring back the grass first. Make sure it looks like you want and if not, tweak the material settings and not play with camera, exposure etc.
#311996
Well, I am sorry but let me re-start following your suggestion from the beginning.
And I made a ball and a chart bar in my scene, and used Lambert grey to the ground as below:
Image

And then, I put the grass texture to the ground as below:
Image

The reason why I wanted to re-start following your suggestion is because I thought from the camera angle in the previous message it would become difficult to see the lower surface of blossom.

(By the way, I just now sent the scene with motion blur bug to you.)
User avatar
By tom
#312015
OK, now the exposure looks good enough. So, the grass is better than the previous attempts except some points. I think it requires to be denser. Now, increase the grass tile and show us the material setup for grass because, it still looks a bit washed out. (Btw, thanks for the scene. I received in email and we will check.)
#312106
Oh my God...
Image

I have to say I am sorry I've forgotten to put the same texture on Reflectance 90 as that on Refl 0 for the grass ground, in spite that I have watched Mr Verta's tutorial...
I re-rendered and this time it should be Okay as below. I am very sorry.
Image

A close look is as below, and I put a teapot with diameter 20cm just for understanding texture size. I should be Okay so far.
Image

And I also put the material setting for grass ground (after putting the same texture on Reflectance 0) as below.
Image
naikku wrote:must say that very impressive for tom/nextlimit to help like this.
i havent seen / heard any company to give this kind of support for customers.
*big thumbs up*
Yes, definitely I agree. I am afraid that I am causing too much trouble to the NL team whose time should be dedicated to more important things...
User avatar
By tom
#312112
koji_maruyama wrote:Yes, definitely I agree. I am afraid that I am causing too much trouble to the NL team whose time should be dedicated to more important things...
No :) Please, don't say that. Because, this is a forum for technical support. So, you're more than welcome.

Now, with more tiling the grass started to show a repeating pattern. In that case, you need a higher res seamless grass texture OR you can still use this one but decrease the tiling until the repeating disappears. Then, unhide on of the trees (only the body of it without blossoms) and focus the camera to it.
#312134
(again from Koji)
Thanks really.
Really.
This time, I decided to use another grass texture, and by modifying the size and shape of that texture and combining many pieces of them, I have created one huge texture of grass, and tiled the ground with that huge texture as below.
Therefore, the general color of the grass has become a bit different from that of grass in the previous message I posted.
The diameter of teapot is 20cm and so the texture size is quite fine, I think.
Image

And I also unhided one of the trees but without any blossoms, and focused the lens on it as below.
Image
I hope this time I could almost erase the "pattern" on the ground.

A close up of the above picture is as below.
Image

Thanks indeed for your guidance.
I wonder if there is something I can do for NL...probably nothing...
Last edited by koji_maruyama on Fri Oct 16, 2009 9:59 pm, edited 1 time in total.

So, is this a known issue?