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pangor
Subject: A comparison rendering outputs.
With the dicussions of various rendering engines I thought it was time for a side by side comparison of the raw output from a few renderers when working on the same scene.
The attached picture shows four version of my recent MBotW work.

In the upper left is the final image as posted in the MBotW gallery (size reduced here) It is a Poser 5 render with postwork applied. It will be our yardstick to measure the raw output of the renderers by.

In the upper right is the same image without postwork. This is the raw render from Poser 5 using firefly.

In the lower left is the same image rendered wity POV-RAY. The entire scene was exported from Poser as a OBJ file and converted to a POV-Ray scene by PoseRay. The Radiosity option selected.

In the lower right is again the same image, this time rendered by Aqsis. The scene was exported as a RIB. Aqsis failed to handle the RIB file. Edited the RIB with a text editor to correct output resolution and to correct the file psths. That second oorrection may not have been required with the use of the Windows version of Aqsis, which bring into question the potability of Poser generated RIB files.

I also tried to run a test render with Pixie. However, it rendered only a solid blackness. I was unable to locate the texture maps, it demands for the textures maps to be in TIFF format. Converting them to TIFF did not help, the rendering program's TIFF reader was incompatible with the TIFF writer of the gimp. Her hair was not removed, the texture was locate, however it appears that even partial transparance is rendered as fully inviisble; or Poser miswrote teh RIB to cause the hair to be invisible. Also the lady was rendered with visible facets and the resulting artifacts. Scaling the image down to fit in this composte image, his most of that problem.

Subject:
Excellent work, Pangor. Had hoped to do something similar.

I think getting Aqsis to work is half the battle. From what I have read, using shaders is what is suppose to really improve output! I have found references to shaders and other program/utilities that require investigation.

I think it may also be time to dust of a couple of old Dos books. I have Borland's C++ for Dos, but haven't done anything with it for ages. Should also take a look at the Unix language structure. Not that these are specifically required, but a better familiarity would be useful for reading some of the technical stuff about the various render engines.

And I need to find a better text editor. Notepad just doesn't handle it.

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pangor
Subject:
I don't know about good Windows text editors. Have not needed any for years. In unix, I use JOE VI and PICO. JOE for its WordStar command key very similar to those you may have used with Borland C and C++ IDE. VI is an old stand by that since long before Windows and is still impoving.

What renderman calls a shader is a small program written in the Renderman shader language. That is why you have the "aqsl" the shader compiler for Aqsis. For the skin the plastic shader was used. This may have been a bad choice by Poser, or it may be the best shader that Poser could count on being available on all Renderman implementation.

The Shader langage does appear to have been derived from C. Between the Aqsis and Pixie, Aqsis has the points for better standatd Renderman shaders since it has the actual shaders distributed by Pixar. However, Pixie has some shaders that are not included with Aqsis, like the glass shader. That is not problem though.

You can easily copy the shaders from one over to the other. But they won't work; until you compile them for that particular renderer. They are written in the same language, in the SL files, but they compile to the local renderer's own internal shader machine code. For Aqsis, the compiled shaders are stored in SLX files and it looks like assembler code for Intel processors for the MASM assemplers. For Pixie that are stored in SDR files and look like a cross between FORTH and IBM BAL assembler code.

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FORTH and BAL. Now there's something I haven't read anything about for a very long time.

I did get a chance to look at some of the Aqsis documentation as well as read some of the history on Renderman.org in the FAQ's. So that plus the information you are providing really helps tie some things together.

I did finally finish editing the rib file and got a satisfactory tho poor render, but really need to set up a test file with backgrounds and proper lighting and figure out why the Transfom command isn't working properly. Then try some shaders. It would be fantastic to get some results like some of the renders I saw in the Aqsis render challenges.

I haven't tried Pixie but will get around to it. Did notice some of the similarities you mentioned.

Well, I know where there is a highly recommended Windows text editor for this kind of work, but it's not free. Haven't found a good freebie so may have to byte the bullet and buy one. I tried the text feature of MSWord, but ended up with an error in the file. Don't know if it was me or Word, but I'd rather have a dedicated editor.

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pangor
Subject:
I found a Renderman skin shader that is in the public domain. It is not production, more like a proof of concept. it's parameters are mostly the same as those of Poser 5 and Poser 6 skin shader node. I have uploded the unmodified shader into PF's freestuff.

I have made some revisions to it making it more functional and also more compatible with the Poser skin shader node. But I did this without reading the docs yet, knowing C was enough for the experimental modifications. The problem with the invisible hair was caused by Poser, on export it made the entire hair model invisible.

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I like to make things too.

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I finally got a good, fast text editor and after I look into a couple of other things, may finally have the time to play with different render engines.

Speaking of render engines, after reading my CAD manuals, I discovered that the render engine is by Lightworks. The next version of my cad program uses the Lightworks 7.5 render engine. Maybe I'll upgrade one last time.

Now, if I could only figure out a way to get stuff in and out properly, I might have something.

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pangor
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I have the same problem with exports from the modeling program that I am most familiar with. The version that I am most familiar with has not export function at all, nor does the version that I use now, however starting with this version the program supports 3D plugins, and I found a worakable plugin for importing and exporting Wavefront OBJ files. Also bryce will import this modeler's native format. However, much of the time, strange things happen to the models when they are are so converted.

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I can import and export 3DS as well as DXF and several other formats. I think what happens to me is when I start trying to group parts of meshes. I got a hint at one potential issue when Poser complained about bad "blocks". I may try to save some of the meshes as blocks and see what happens. Poser doesn't always like the 3DS files my cad saves directly, so sometimes they go thru Pose Ray for conversion.

It's a never ending learning curve. :roll:

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pangor
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True, oh so true.

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Thank you pangor, I'll bookmark this topic because I want also to show some differences, but with the different options of the Poser render engine. I think that the best output is the first with Poser and the best one is obviouly the first one with postwork... For my next picture I'll save the WIPs before the postwork

Subject:
With the addition of Renderman compliant shaders to Daz Studio, and an upgrade of the render engine to the 3D Delight stand alone version, I wonder if new scripting features of D/S would allow using the public domaain shaders?

:mmmh: :mmmh: Another thing to add to the oversized list of things to do. :wink:

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Why not lying on the sofa watching TV instead :mmmh: ? :yes:

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That gets done once a week during the NASCAR races! :lol:

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:eh: Uh? (Tormie is far from the PC on the sofa :tv: :tv: :tv:)

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