question

Frank Vitale avatar image
Frank Vitale asked ·

Help with Emissive shader in Max

I've a few problem with the emissive shader in Max 2018

- Object with emissive shader is casting a shadow from another light in my scene, I've unchecked "cast shadows" under object properties but it's still casting a shadow.

- No way to exclude objects from a light in Arnold??? This is hard to fathom. I've been excluding objects from lights for 20+ years ???

- How can I control the amount of light an emissive shader emits? It seems that upping the number under Emission does the trick but it's really noisy, can I adjust the samples?

- In trying to have no emission of light but still full luminosity on my object, I've reduced the Indirect Diffuse under Basic Parameters to 0 but I'm still seeing light being cast.

As a side note I'm not understanding why Arnold has been brought in as the default render engine for Max and Maya... to this 25 year vet it feel like a step back 30 years. I've been using it now for a few months and feel that I have a passable understanding of it's features and am feeling that it lacks some of the most basic functionality that has been around forever. I was doing things in the 90's that I can't do now - it's quite absurd to be honest. My main career tool is now completely broken. It's very frustrating.

renderlightmaterials
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Frank Vitale avatar image
Frank Vitale answered ·

Another question... is it possible to apply volume to a single light? It seems that volume is only avaiable globably, if this is the case it's seriously limited.

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Frank Vitale avatar image
Frank Vitale answered ·

For those wondering... I did figure it out, you need to set the Vol contribution for all lights you dont want to have volume to 0... makes sense.

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Michiel Van Gasse avatar image
Michiel Van Gasse answered ·

Use a arnold properties on the object, use light group to exclude lights.
You cannot adjust samples for a shader/material, use a meshlight instead.
Use a arnold properties on the object, disable diffuse reflections to not illuminate on other objects from the emission.
You can still use mental ray/scanline, but arnold is way better in render quality.

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Lee Griggs avatar image
Lee Griggs answered ·

> How can I control the amount of light an emissive shader emits? It seems that upping the number under Emission does the trick but it's really noisy, can I adjust the samples?

Increase the number of Diffuse samples.

>- In trying to have no emission of light but still full luminosity on my object, I've reduced the Indirect Diffuse under Basic Parameters to 0 but I'm still seeing light being cast.

Did you reduce Indirect Diffuse for the shaders on which it is cast?

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Lee Griggs avatar image
Lee Griggs answered ·

>I was doing things in the 90's that I can't do now - it's quite absurd to be honest.

Can you give an example?

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Stephen Blair avatar image
Stephen Blair answered ·

Object with emissive shader is casting a shadow from another light in my scene, I've unchecked "cast shadows" under object properties but it's still casting a shadow.

If I add an Arnold Properties modifier to an object, and clear the Casts Shadows check box, then that object no longer casts shadows.

I don't know how to reproduce your problem, so can you upload a simple example?

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Frank Vitale avatar image
Frank Vitale answered ·

Thank you @Michiel Van Gasse but where do I access "Arnold Properties" and "light group" and "diffuse reflections" ? Clearly Arnold has great depth, unfortunately the documentation does not... it assumes the reader already knows the software and leaves one digging endlessly for answers. Also I appreciate your take on the quality of Arnold as a renderer... but I've had a very different experience. I've been creating photo real works for a couple decades using Mental Ray, it give one a great deal more control and much clearer language. I want to learn Arnold but it is proving very difficult. I spend 15 hours trying to achieve a look that I can accomplish with greater accuracy and predictability in two hours with MR. I mean, we cant even preview reflectivity in the material editor, working blind is no fun at all. Mograph seems to have a failry complete tutorial set for a fair price, I'm going to give it a try. http://mographplus.com/product/comprehensive-introduction-to-arnold-for-3ds-max/

Thank you @Lee Griggs the hot link was helpful and I was able to better understand this pipeline and effect. I did not "reduce Indirect Diffuse for the shaders on which it is cast" Is that how it works? That seems crazy... what if you have 100's of effected objects? Seems like a very sloppy way to achieve desired results. To see examples of my work have a look at my site www.33north.net most of it is MR and Max, some is Cinema and some goes waaaay back to the Strata days. It really is frustrating that things I was doing 20 years ago are more challenging now - to me this makes no sense at all. I've taught CGI at multiple schools, I know this industry like the back of my hand and the new tools are just not as easy to use or predictable as the old tools.

Thank you @Stephen Blair I did not know how to get to this... how is one to know that is modifier based without stumbling across it? Thank you!

I appreciate all the input, seem this is a very responsive forum...

Frank Vitale

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Stephen Blair avatar image
Stephen Blair answered ·

https://docs.arnoldrenderer.com/x/vYJsAg

You can access the Arnold Properties modifier like other 3ds Max modifiers.


Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Stephen Blair avatar image
Stephen Blair answered ·

In trying to have no emission of light but still full luminosity on my object, I've reduced the Indirect Diffuse under Basic Parameters to 0 but I'm still seeing light being cast.

If I understand correctly, I second what @Michiel Van Gasse suggested:

Use a arnold properties modifier on the object, disable diffuse reflections to not illuminate on other objects from the emission.

And maybe disable specular reflections too.

Here's a torus over a grid. The torus has a Standard Surface shader and Emission = 1.0

On the torus, I disabled "visible in diffuse reflections", so now we have just the spec (so if I turn off "visible in specular reflections" too, then the grid won't get any lighting from the emissive torus).


emissive-object.jpg (16.5 KiB)
Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Ice Juice avatar image
Ice Juice answered ·

Why you do not integrate Light/Shadows Include/Exclude directly into the Light setup, using the modifier for this is extremely inconvenient, I have not seen any render in 3ds max, so that this function would be implemented as ugly as you have. Arnold is an amazingly powerful and flexible renderer, completely awfully integrated in 3ds max

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Write an Answer

Hint: Notify or tag a user in this post by typing @username.

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Welcome to the Arnold Answers community.

This is the place for Arnold renderer users everywhere to ask and answer rendering questions, and share knowledge about using Arnold, Arnold plugins, workflows and developing tools with Arnold.

If you are a new user to Arnold Answers, please first check out our FAQ and User Guide for more information.

When posting questions, please be sure to select the appropriate Space for your Arnold plugin and include the plugin version you are using.

Please include images, scene and log files whenever possible as this helps the community answer your questions.

Instructions for generating full verbosity log files are available for MtoA, MaxtoA, C4DtoA, HtoA, KtoA, and Kick.

If you are looking for Arnold Documentation and Support please visit the Arnold Support site.

To try Arnold please visit the Arnold Trial page.

Bottom No panel present for this section.