Cineversity

Hi there,

I’m having a series of issues with proRender [R21 (303831)MAC - Radeon PRO WX7100 and/or PRO 460 - produce same issue] results when
1. Normal map channel is used -seems same with bumps - I’m using Megascan objects with fantastic level of detail maps, including normal and bump. However using it either in the outside Normal or inside the reflectance chanel with bump strength - mode (normal map), does not show any effect in the final render. Funny enough the viewport shows better with the right strength than the render. Any idea? Is this a bug? A still missing badly implemented part?

2. Alpha channel. I have quite an amount of beautiful Laubwerk tree packages and they all come with alpha channel leaves. I understand they are not coming with PBR materials so I properly convert them, but when alpha channel is used for the leaves, I get a terrible result with greenish sort of inverted look in the rendering. As soon as the alpha is turned off, renders fine. I tried to play with different alpha channel settings but the results are the same. seems also if I turn off the Firefly filter, the green inversion pictures turns into a bunch of red dots.

3. Backlight shader. Laubwerk trees leaves uses backlight shader in the luminance channel to get shadows shine through the leaves. (if this is a proper way to explain) however seems this has zero effect when provender is used. Is the backlight shader implemented?

Any suggestions or tips to solve this would be appreciated.

Hi MSZ,

As usual, a question without a scene file leads to guessing, which I consider not professional. I can however, give you some pointers, as in the two scene files below.
Project files:
https://www.amazon.com/clouddrive/share/0AUXjhmMdCBSE2K2lTFX72p310iyqBDy2xavqgUcZxO
The file [01] contains an exploration with Normal v. Bump maps.
The file [11] explores the alpha channel. Not that I have set the ray values higher.

If you like to share your file, reduced to the core problem, I can give you an upload link. (Amazon, Dropbox, Apple, Adobe, Google, and WeTransfer are the ONLY could services I touch at the moment.)
At the moment I get your file, I’m happy to explore it.

Since I have no idea what you have set up, let me share one suggestion, perhaps change the Epsilon value (increase) are the artifacts gone? (End of guessing.)

The ProRender has a list of limitations, here:
https://help.maxon.net/us/index.html#56141
Scroll down. I have listed the relevant entries for your questions below.

However, the main idea could be boiled down to that one needs to bake many results that are given with Standard or Physical Render. In terms of tree-leaves, that would require a large UV map to give each single leave enough space to produce the Backlight results.

Limitations: (three points of the longer list)

The Bump channel’s Parallax effect is not supported; in the Normal channel, only the Tangent Method is supported; only a portion of the Displacement channel’s SubPolygon Displacement settings is supported. Displacements can end up looking a little different from that of other renderers.

ProRender has to convert very many 2D bitmaps (most shaders don’t run natively on graphics cards) in order to process them. This works better for some shaders than for others. Shaders that don’t use UVs (e.g., 3D noise), several that depend on the angle of view (e.g., Thinfilm), that require light (e.g., Chanlum, Subsurface Scattering), that require scene data (e.g., Variation and other MoGraph shaders) and those that are calculated during rendering (e.g., Ambient Occlusion) will not deliver satisfactory results (wee also Texture Size X in conjunction with settings for converting these shaders to bitmaps). Bitmaps are not cached, they are created new for each rendering, which can require a lot of time. These shaders are not affected because they are rendered using the graphics card: Color, Bitmap, Tile, Normal Direction, Noise (only 2D modes), Gradient (only 2D modes) and Fresnel.

Note that ProRender reacts somewhat more sensitive to polygon Normal rotation than the other renderers. If you experience unexplainable render results, double-check the Normal orientation.

If all of that is not leading to something, and you can’t share the file, please check with the support about the render artifacts.
https://www.maxon.net/en/support-center

My best wishes and enjoy your Sunday

Hi Dr. Sassi,

Apologies for not adding any project file to the question. I wasn’t sure about how Laubwerk and Megascan objects are licensed in a public forum and also if the textures would pass the limit here.

Generally speaking, I’ve tried and by now I’m pretty familiar with the restrictions.
The backlight shader since it’s in the Luminance channel, might be a dead end, but please look at it in my example file.

Would you be able to provide me a link for upload?

Thank you for you help, as usual!

Hi MSZ,

I have sent an upload link. (Dropbox will send an email when new material is upload, no further action needed)

Any file that has the name private in it, will not be shared public-ally from my side (nor will I share it internally anywhere). Yes, that limits the way the forum works for anyone, but most of the time, that helps me to see what happens. In other words, if I can recreate and solve it, I can certainly set up a file from scratch that can be shared without violating any copyrights.

Yes, I believe the Backlight Shader kid of disables the idea of a fast render. No idea if there might be a newer idea one day. Maxon’s Support form has a suggestion option, and Maxon likes to hear what is needed and wanted!
https://www.maxon.net/en/support-center
Perhaps a specific texture-pattern will help to simulate this.

I will have a look at it. Please note that I’m on L.A. Pacific Time (PDT).

My best wishes

Hi Dr. Sassi,

thank you again for your help.

1. I solved the Alpha Chanel issue. it was that pesky ray epsilon value. Dialling in 1000mm solved my issue.
2. The normal map is still a problem and I sent you the file.

Best,

Hi Dr. Sassi,

regarding #2 normal map. If I increase the value from 100 to 10000 or 100000% seems like I would get the correct result. this would suggest a scaling issue?

Hi MSZ,

Thanks for the file and yes, I will keep this private. Any example below will be based on my set up.

I’m glad the epsilon value, as suggested, worked.

Try the following for the Normal exploration.

Remove the material from the stone.

Create a new material, check all channels off, except for the Reflectance Channel.
Delete all Layers. Call up a new Beckman and set the Roughness to 0%.

Apply this to the stone. Render in ProRender.
Now apply the Normal map to it, render again.

Switch the Normal off.
Delete the Normal Texture.

Somehow, in the material I got, I was not able to shut off the Normal, it stayed inside active as if there was a piece of bump information. [sic]

I have created a screen capture,
https://www.amazon.com/clouddrive/share/hEyJOV1V2rcOn4rGfNdb1Akty8qJawf6C4a8kI3PE3G

Cheers

P.S.: Yes, scaling, what is the right one? If you switch to the Standard Render, those high values will be way over the top for Normal. Even Bump cranked up high is different in each. After all, it is not really something that is based on exact measurements. Normal values just direct the rays as is the surface-direction would change, but after all, as with Bump, the actual surface is the same as if nothing (Bump or Normal) would have been applied.

thank you Dr. Sassi,

very helpful tips and suggestions.

I would lie if I say it’s all clear to me, as I was playing around with the default unit size (from cm to m) and it did have visible impact with the default 100% normal value, and cranking it to 1000% would make the ProRender result equivalent with Stand/Phys 100% value. I know it doesn’t seem to make sensel, but it works. Also seems like the normal map has only influence in the Reflectance channel, and need to be applied on all layers if more than 1 reflectance layers are used.
Does this make sense to you? Maybe this is one of the reason the Quixel bridge does not support ProRender just Stand/Physical and Redshift/Octane connection.

Hi Dr. Sassi,

I again retried it, the default unit does not effect the strength of the normal map. but I still have to apply 1000% to get normal map cracks as visible as it would be in Standard/Physical. I definitely think this is a problem in ProRender implementation. I’m surprised that I’m the only one who sees difference between how normal map is applied in Physical/Standard vs. ProRender. the difference is so visible.
I’m getting r22 hopefully today and see if proRender would have an update. I put this aside for the time being.

Thank you for your ongoing help here.

Best wishes,

You’re very welcome, MSZ, thanks for the reply.

Bump and Normal mapping, are not changing a single point or anything on the surface. This becomes clearly visible in the silhouette of the object. A sphere shows up as a circle-like shape on its borders. There is no bump or normal technique that would change that.
The best effect is given when the camera is set perpendicular to the surface. Anything else will lose more and more quality.

Strong values (as we have seen) this is relative to the rendering algorithm used, should never be set very strong. Again strong is not an absolute number here, as it depends on the scale of the texture to the object, the view angle, and other influences.

These techniques are used for minor details of an object and can support and otherwise less detailed Subdivision-Displacement. If mixed well, it can create a synergy effect.

To use the only Displacement here would stress the render-engine a lot. So a good balance is needed. For me, the Pro-Render is a concept that gives you quick feedback and can be used accordingly to provide fairly good render-times.
I have problems seeing the quality that I get from other render engines in it, considering its shortcomings. See the list of limitations.
To see how much RedShift is taking place these days, it needs no further exploration of the position that the ProRender will take.

To your layer question:
Please have a look at this clip:
https://www.amazon.com/clouddrive/share/CThPUXrpFbGQoWyyVwYSAJqtC9G92jGwmHk77GefJu6

I have set up three Layers in the Material, R-G-B are split here and then summarized (add) to be color neutral. If one layer didn’t get the Norma-Map information, the result would be very colorful.

If you call many materials layer, then yes, each material needs to calculate the Normal Mapp on its own.  As mentioned above, it is a calculation, not a surface change.

A Normal Map provides the surface orientation, expressed in vectors, as RGB values, each color is one direction R=X, G=Y, and B=Z. This is read and used like the Phong tag information.

I hope that helps

All the best

P.S.: you wrote while I was replying to the previous post. Since the values are relative, and typically one picks a render method and stays with it, for the time being, it doesn’t surprise me at all. There is nothing that I can do here, and even if I’m not supposed to. This is purely a Support question.
https://www.maxon.net/en/support-center