Color Mapping Parameters

[andreyluccahannes]

Hi ,

it seems that the documentation for the Color Mapping Tab is not adjusted for the Houdini Version


In houdini there is no burn value. So how do I adjust the blend between reinhard and linear color mapping mode?
And also the Colors Multiplier do have an effect on the rendering when reinhard is selected even though they shouldn't as in the help specified.

Can someone clear this up for me?

Greetings Lucca

[piotrus3333]

the idea for last few years is that you do your tonemapping in VFB and leave those settings (Color Mapping) on defaults.

[Jon3D]

We do not use the VFB for grading/tonemapping for now. Btw. are the settings of the VFB respected if you later render your images without buffering them to VFB?
It would be nice to know how the parameters in the rop in fact do affect the image since they apparently do different things then the help says.

[bdancer]

> are the settings of the VFB respected if you later render your images without buffering them to VFB?

They are even stored in the vrscene file.

> since they apparently do different things then the help says.

They are not doing different thing.
We have to adjust labels in the docs sections though (since we don't change labels dynamically yet...).

[Jon3D]

>They are even stored in the vrscene file.

Oh thats interesting I didn´t know that.

which parameter controls the blend value at the moment when using reinhard Mapping?

[bdancer]

> which parameter controls the blend value at the moment when using reinhard Mapping?

"Bright Colors Multiplier". I'll rename this parameter to "Bright Mult. / Burn Value".

[Jon3D]

>I'll hide dark mult if Reinhard is selected and rename parameter to "Bright Mult. / Burn Value"

While doing that can you please double check.
The picture below is rendered with exponential color mapping. The region on top is rendered with reinhard "bright colors multiplier" set to zero. Which should blend 100% to exponential right? But the result looks different.

[bdancer]

> But the result looks different.

"if Burn Value is 0.0, the result is exponential-style mapping"

Well, docs say "exponential-style" not "100% as Exponential mode".
It's the same in 3dsmax, so I guess this is how it works.

[piotrus3333]

Reinhard with burn 0 = Exponential in 3ds max.
also bright/dark colors multipliers were always separate controls from burn.

[Jon3D]

>Well, docs say "exponential-style" not "100% as Exponential mode".

Ah. I indeed expected "exponential-style" and "exponential mode" to be the same and never did a comparison between them in max back then.

Thanks for the hint.

[bdancer]

piotrus3333, well, I've tried it in 3dsmax and it's not 100% the same, could you pls double check it?

[Jon3D]

>well, I've tried it in 3dsmax and it's not 100% the same, could you pls double check it?

I did also double check it. Its not the same on my end.

[piotrus3333]

piotrus3333, well, I've tried it in 3dsmax and it's not 100% the same, could you pls double check it?

you are right. something is wrong with Exponential in Color Mapping settings. Burn = 0 in both the settings and VFB give the correct result y=x/(x+1).

[piotrus3333]

it must be a bug. there would be no point in changing this suddenly.