Reinhard colour mapping workflow?

V-Ray V-Ray for 3ds Max General
1

Hi All,

just been playing with the Vray1.5 demo today, while waiting for my dongle to arrive.

Does anyone know how Reinhard colour mapping works and can it be used with LWF?

cheers all

2

Are you telling me that you can use 1.5R2 without the dongle? How?

Thanks.

3

yep, theres a demo a avalable,

http://www.chaosgroup.com/support/private/vray/demo/150R2/80/

4

not working now :(.. must have beed removed

5

mdi, try www.vismasters.com

6

Matt, ive played around a bit with Reinhard mapping.
I had the Gamma in veiwport preferences set to 2.2, Set Reinhard Multipler to about 4-5 and Burning value to what ever suits (about 0.4-0.6 is quite nice), Rendered in VFB with sRGB ticked.
Then Save in what ever format, overriding the default gamma in the save window to 2.2
Thou im not sure if this is correct LWF, the results are nice!

7

cheers

Jow, was that you kitchen image that you used those setting on? is a great image

base2studios,
cheers, theres a Demo 1.5 on there site if anyone intrested

8

That is Linear Workflow - with the SRGB button checked. Im not sure how the multiplier and burn values effect the secen however. Are you using the physical camera? Exteriors? Interiors? Both?

9

ahhh,

so… does the SRGB button turn the image from 1 gamma to 2.2 gamma.. It looks like its doing that anyway?

10

Yeah, but also with a lil bit of PS cc aswell…Thanks…

The sRGB does turn the IMG from 1.0 to 2.2 gamma, but you need to save the IMG with 2.2 Gamma or add in post.

Jujubee, I’ve only tried it on Interior scenes with the Vray cam. But like say , due to the multipler and burn changes i made im not to sure its 100% correct LWF. But if it looks good, its good enough…

11

Leave the Reinhard as standard apart from the burn value, set it to 0.2.

12

and turn on SRGB?

btw, are you guys using colour correct plug set to 2.2 with it ?

13

no we dont use any colour correct plugins or use the srgb, nor the linear workflow..

14

I think reinhard may be employing gamma 2.2 by default so it would be LWF without the SRGB button. However, Jow me be recompensating for that value by adjusting the multipliers and checking the sRGB button.

It’s a question left for Vlado/Peter.

15

What i’d like is an explanation of what it does to the image and how it works.

I dont like sticking to rules when rendering. :smile:

16

Hey Natty, How’s things? U keeping busy..
Dropping the burn value that low, wouldnt it be the same effect as using Exponential mapping?
Do you compensate for this with higher light multiplers?

17

The Reinhard color mapping does not apply any gamma transformation on the result. Here are some curve graphs demonstrating how different color mapping modes work. The x axis is the input (original) image color, and the y axis is the output (color-mapped) color.

Useful observations:

  • In the last image, although this is not clear from the limited graph window, neither the Exponential, nor the Reinhard with Burn 0.0 curve ever go above the 1.0 (white) value (e.g. no burnt-out areas). However, the Exponential graph goes very close to white very quickly, while the Reinhard curve is more gradual.
  • Near the dark colors, the slope for both Exponential and Reinhard modes is similar to the slope of the linear mapping, which means that those modes preserve darker colors near their original value.
  • When the Burn value is 0.5, the Reinhard curve intersects the y=1 line (the white color) when x=2 (the original color has an intensity of 2); when the Burn value is 0.2, the curve intersects the white line for x=5; the same relationship is true for any other color and allows you to choose presicely the values of the colors that you want to be mapped to white.

Here are larger versions of the images:

Best regards,
Vlado

18

:shock:

19

That was suprisingly informative in general, thanks.

20

Thanks for explaining what the burn value does Vlado, what about the multipler? Is this similar to what the light/dark multiplers do for the other colour mapping types?