My first comp (beginner question)

Hi all

I'm trying to make a simple composition in Fusion.
I created this sphere ( modo 3d) and exported all the passes as TIF images.

I did the merge like you can see in the attached image.

I can't see exactly why is my comp (left image) different from the final render that modo did (right image).
I know it has to have something to do with the gama....

Thanks and congrats for fusion I'm enjoying it very much .
Madeira3d

In the modo manual says this:
The question most often asked is "Which Render Outputs combine to equal the Final Color output?" The answer is "Diffuse Shading (Total) + Transparent Shading + Reflection Shading + Specular Shading + Subsurface Shading + Luminous Shading = Final Color", where each successive layer is added to the layer below in the composition (also called Linear Dodge). Rendering each layer at a gamma of 1.0 and then combining them and adding the gamma back to the fully composed layers will produce the best results.

The modo instructions are weak. Linear images composited together with the math they gave doesn't make the "best" result, it makes the correct result. Not your fault, just bad documentation...

Anyway, are you certain your images are linear?

Hi Chad, thank you for the reply.

You are right, the final render from modo was in sRGB color space, wile the other render outputs were Linear.

I found out that if I apply a Add Tool>Color>OCIOColorSpace to image on the left it will become exactly like the image on the right (the modo final color with sRGB).

So the recap, the right way to do things is to work in Fusion with the linear images and in the end just add a OCIOColorSpace to convert it to sRBG right?

Thank you
I think I´m liking Fusion quite a lot

Madeira3d

Seems like you forgot the last step: add gamma (via viewer lut or gamut node to srgb). By the way, what bit depth are your tiffs? Linear comps require floating point which is usually stored in exr files (they don't support other formats but tiff does which might accidentially cause banding when you're adding gamma)

Seems like you forgot the last step: add gamma (via viewer lut or gamut node to srgb). By the way, what bit depth are your tiffs? Linear comps require floating point which is usually stored in exr files (they don't support other formats but tiff does which might accidentially cause banding when you're adding gamma)

But neither has gamma added in the flow or viewer. So one would have to have gamma added and the other not, which is odd, but maybe Modo is odd.

TIFF can be float, just like EXR can be integer. Need to verify either way.

EDIT: And gamma won't constructively affect values <0 or >1, so integer is fine for linear images, so long as the precision is there.

Hi Chad and Stefan

Sorry for the delay to reply but since i was a new user my posts always needed authorization.
I think now I'm clear from the authorizations and can post and reply immediately.

Let me know if my English above with the explanation was clear, if not I can post some images to explain but it's working fine.

Thank for the great help
Madeira3d
https://www.behance.net/paulomadeira

Welcome, Paulo. The explanation is clear

So that workflow is fine, but it's not the only way to do it. The Gamut tool could also work, as could setting the colorspace in the Saver. If you want to use the LUT in Viewer, that's good too, it affects whatever ends up in the viewer, but it doesn't affect the output. So there's a few options, I'm leaving out others that are less ideal.

Thanks Chad

I'm still overwhelmed by all this nodes and trying to understand the most basic things but It's time well spent.

I will have to come back to this email in the future and try to fully grasp the other options you mentioned. Not it's time for some youtube videos and try to learn a bit more.

Thank you for the help.
Madeira3d