Results 1 to 6 of 6

Thread: Trying to survive with Iray... Beginner's journey...

  1. #1
    Join Date
    Aug 2017
    Posts
    12

    Default Trying to survive with Iray... Beginner's journey...

    Hey all!

    I already use Iray for substance to make my beauty renders. The thing is I really would like to animate the characters I make with the same render I have in Substance (and Damn! That's a very pretty render engine!).

    Click image for larger version. 

Name:	Wip011.jpg 
Views:	37 
Size:	220.4 KB 
ID:	9675

    And there it start. I've got many struggles and for now I can't achieve anything good with Iray for maya.

    The normals were a pain in the a**. A Good fellow helped me and yes it works, but now the normalmap is ugly as hell (needed to push to gama 2.2 in RGB channel lot af loss....)

    I think the color map works, and the roughness, well maybe. But where is my metallic channel? Got specularity channels, but it's not what I want.

    Here is where I am now. With the nodal system in the hypershade.

    Click image for larger version. 

Name:	Sans titre-1.jpg 
Views:	35 
Size:	322.8 KB 
ID:	9676

    Far from...

    Click image for larger version. 

Name:	dfsc.jpg 
Views:	36 
Size:	177.8 KB 
ID:	9677

    So here is my questions :

    1/ is there a way to avoid pushing the gama of the normalmap (another export setting? What is the format and the color space needed?)
    2/ how can I add the metallic value? i don't see it.
    3/ is there a better way to start a material with metallic roughness?
    4/ can somebody tell me what is the good workflow and what I have to understand to create the good material to achieve the substance render quality.

    I would take any hint or tips!

    Thanks

    Pierre

  2. #2
    Join Date
    Jul 2013
    Location
    Germany
    Posts
    90

    Default

    Hi piotr47,

    personally I'm not a great Substance Designer expert. But I think that the reason for your problem is the template you use when starting a project in Substance Designer. When starting a New Substance you have the choice to choose a template. I guess you choose Physically Based (Metallic/Roughness) which is the correct one for material used in games engines.

    When using off-line renderer like Iray for Maya you need to choose Physically Based (Specular/Glossiness) to get the same result as in Substance Designer.

    The reason is that the texutre written by Substance differ for each of the chosen templates. To get a better understanding about this I recommend the document "PBR_volume_02_rev05.pdf" by Allegorithmic. I added a screenshot from this document to illustrate the difference I mean.

    Click image for larger version. 

Name:	pbr.jpg 
Views:	37 
Size:	97.7 KB 
ID:	9680

    I guess that Substance Designer offers a workflow to convert your Substance from Physically Based (Metallic/Roughness) to Physically Based (Specular/Glossiness) but I'm not sure about this.

    We will check how to improve this workflow from our side in the future.

    Does this help?

    Regards

    Chris

  3. #3
    Join Date
    Aug 2017
    Posts
    12

    Default

    I'm trying to survive this forum too. I cannot post a private message (fuchs ask me my email but I can't send back a private message.......), but account had been already activated, and right now moderation have to approve everyone of my post...

    If the moderator see this message here is my email of the account. maugerpierre@yahoo.fr

    thanks.

  4. #4
    Join Date
    Aug 2017
    Posts
    12

    Default

    Quote Originally Posted by cberndt View Post
    Hi piotr47,

    personally I'm not a great Substance Designer expert. But I think that the reason for your problem is the template you use when starting a project in Substance Designer. When starting a New Substance you have the choice to choose a template. I guess you choose Physically Based (Metallic/Roughness) which is the correct one for material used in games engines.

    When using off-line renderer like Iray for Maya you need to choose Physically Based (Specular/Glossiness) to get the same result as in Substance Designer.

    The reason is that the texutre written by Substance differ for each of the chosen templates. To get a better understanding about this I recommend the document "PBR_volume_02_rev05.pdf" by Allegorithmic. I added a screenshot from this document to illustrate the difference I mean.

    I guess that Substance Designer offers a workflow to convert your Substance from Physically Based (Metallic/Roughness) to Physically Based (Specular/Glossiness) but I'm not sure about this.

    We will check how to improve this workflow from our side in the future.

    Does this help?

    Regards

    Chris
    Hey, thanks for the answer.

    Tried a few things. ideed the mat is not the right setup. Tried an IFM opaque material, and it's not the right thing to do, doesn't display metallic channel.

    So I tried a flexMaterial (in the Nvidia core definition if I remember. Almost there. The metallic is activated, it's almost that kind of render, but the specularty is kind of broken or doesn't work as I intended.

    And ther I tried the phisically metallic roughness in alg materials textures. And voilĂ*! Everything is here, I've got almost the right render, I have just a weird glossy effect I have to get rid of and it will be perfect.

    Here it is at the moment.

    Click image for larger version. 

Name:	01.jpg 
Views:	35 
Size:	236.5 KB 
ID:	9681

    So here is a few leads to questions :


    1/ is there a way to avoid pushing the gama of the normalmap (another export setting? What is the format and the color space needed?)
    Yep use .EXR. And , of course the good material.

    2/ how can I add the metallic value? i don't see it.
    Use the good material.

    3/ is there a better way to start a material with metallic roughness?
    Yep, and if you come from Substance, sue the phisically metallic roughness material.

    4/ can somebody tell me what is the good workflow and what I have to understand to create the good material to achieve the substance render quality.
    Use the good material. Work in progress!


    I will try the few tweaks to get rid of the weird glossiness, and I will come back!

  5. #5
    Join Date
    Aug 2017
    Posts
    12

    Default

    Episode 2

    Tried a lot of things, and I am right now quite satisfied with the render settings in maya.

    2 renders with IRFM



    Tried some testing, there is almost no difference with Iray in substance, so quite happy!


    Now this is my setup.



    Base color is a PNG 8bits, space color sRGB
    Metallic is a 8bits PNG, space color sRBG
    Roughness is a .EXR 32bits, space color sRGB
    Normal is a 32bits EXR, space color raw.

    Now the thing is to understand and correct if there is a better way (EXR works great, but the size of the picture!!!).

    Can someone explain why colorspace and type file are so drastically different ine the renders? What is the best type of file to import in maya?

    Thanks!

    Pierre

  6. #6
    Join Date
    Oct 2015
    Posts
    21

    Default

    Hi Pierre!

    First of all, color space of Maya's file node isn't supported in IFM.

    The RGB channels of all 8 bit files are linearized by Iray assuming a gamma of 2.2. 32 bit RGB channels are assumed to be linear already and are left unchanged.

    E.g. you have a raw (linear) normal map saved as 8-bit png. Then you have to use a gammaCorrect node with 2.2 for all three channels before piping it into ifmNormalMapping. That's the reason why this gammaCorrect node is added when creating an ifmNormalMapping node.

    Hope this helps a bit to understand what is going on.

    -Thomas

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •