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Blur1
08-21-2004, 06:23 PM
Like many I'm considering getting XSI Foundation for using in my spare time. I don't have a PC at the moment so I can't DL the 30 day demo.
As far as a renderer's ease of use, my background is as a designer so I'm not inclined towards being a TD/programmer - what's important to me is a renderer that is easy to set up, is fast and produces amazing results.

Most of my experience with 3D renderers comes from Electric Image's "Camera" renderer which I found to be easy to use, of a high quality, and also very fast. The only "easy to use" renderer I have come across that compares is VRay.

I have seen some really nice animated output done with XSI/MR but the one thing lacking was the motion blur. I have heard that the quality and the speed have improved dramatically in XSI 4 with "rapid motion blur". Is this the case? Can anyone post an example with render times? What I have seen before is a huge render hit, and the results still were not acceptable.

Also, is it fast/easy to set up good buffer shadows/aa etc? You know, basic production issues that people love prMan for.

Lastly, how much of a performance boost is there when using the satellite rendering feature in the render region? I know this is not in Foundation but I'm still interested to know. The render region looks like a great time saver and much more fluid than Maya IPR.

Thanks

Atyss
08-21-2004, 07:36 PM
>>>> Most of my experience with 3D renderers comes from Electric Image's "Camera" renderer which I found to be easy to use, of a high quality, and also very fast. The only "easy to use" renderer I have come across that compares is VRay.

First, you will find mental ray not as easy to use as a lot of other renderers. Although you'll get the job done with the default parameters, you'll find that you will oftenly have to optimize to get better speed or lower memory usage. As soon as you dive into this stuff it becomes a technical task. It can take years to really understand the mechanics of mental ray to get the most out of it.


>>>> I have seen some really nice animated output done with XSI/MR but the one thing lacking was the motion blur. I have heard that the quality and the speed have improved dramatically in XSI 4 with "rapid motion blur". Is this the case? Can anyone post an example with render times? What I have seen before is a huge render hit, and the results still were not acceptable.

Motion blur has always been good, but amazingly slow. With rapid motion scanline rendering it can be faster. Rapid motion scanline also speeds up rendering high polygon count scenes, and also can make hairs look better. The problem with rapid motion is that it's supported througout the entire software, for example you can't create alpha masks when using rapid motion (you need to use a custom shader, and someone has to write one!).


>>>> Also, is it fast/easy to set up good buffer shadows/aa etc? You know, basic production issues that people love prMan for.

What do you mean by buffer? If you mean a pass, yes it's quite straigthforward.


>>>> Lastly, how much of a performance boost is there when using the satellite rendering feature in the render region? I know this is not in Foundation but I'm still interested to know. The render region looks like a great time saver and much more fluid than Maya IPR.

The performance will be interesting when you render shots that can take a while to complete a single frame. The thing is that there is a network transfer thing that seem to stop everything before the rendering starts, then the boost shows up once the rendering starts.


Cheers
Bernard

Blur1
08-21-2004, 08:24 PM
Bernard, thank you for your informative reply.

>>>>First, you will find mental ray not as easy to use as a lot of other renderers. Although you'll get the job done with the default parameters, you'll find that you will oftenly have to optimize to get better speed or lower memory usage. As soon as you dive into this stuff it becomes a technical task. It can take years to really understand the mechanics of mental ray to get the most out of it.

I don't expect it to look great with the default params, but as long as it's not too difficult to knock it into shape for a typical SOHO artist. Tweaking mr for maya in 5.0 I found it very hard to get good dmap shadows. Ray traced looked fine but I don't want to have to ray trace everything.

If Soft are pitching towards single users with Foundation then mental ray needs to be able to perform acceptably on a single machine at broadcast res (and up) with good mblur, aa, sampling, dmap shadows, etc. Basically non-exotic core renderer functionality. That is what I'm curious to know. I take it for granted that there will be a lot of tweaking required for FG and such.


>>>>Motion blur has always been good, but amazingly slow. With rapid motion scanline rendering it can be faster. Rapid motion scanline also speeds up rendering high polygon count scenes, and also can make hairs look better.

I have never seen a good example of mr motion blur. Here is a typical example of what I have observed (from the Ed Harriss XSI 4 review):
http://www.edharriss.com/xsi/4point0_images/mexico.jpg
It looks too grainy. I have talked to some Soft users who think that this kind of thing is high quality though. Do you have a link for a good example?

>>>>The problem with rapid motion is that it's supported througout the entire software, for example you can't create alpha masks when using rapid motion (you need to use a custom shader, and someone has to write one!).

Hmm, that's no good, I like to comp 3D. I have seen the La Maison post-motion blur shader, this seems like a good solution in many situations. But if you can't get good MB in an acceptable time frame in render passes, then this is a deal breaker for me.


>>>>What do you mean by buffer? If you mean a pass, yes it's quite straigthforward.

I mean depth map shadows...some EI users call them buffer shadows :)

Michael

Atyss
08-21-2004, 09:17 PM
>>> I don't expect it to look great with the default params, but as long as it's not too difficult to knock it into shape for a typical SOHO artist. Tweaking mr for maya in 5.0 I found it very hard to get good dmap shadows. Ray traced looked fine but I don't want to have to ray trace everything.

Well, mr for XSI is the same as mr for Maya. It's mr. So you'll find the same challenges in XSI than with Maya. The only difference if the toolset (Render Tree) to work with mr is a lot more developed. But overall it's pretty much the same shaders with the same problems.



>>>If Soft are pitching towards single users with Foundation then mental ray needs to be able to perform acceptably on a single machine at broadcast res (and up) with good mblur, aa, sampling, dmap shadows, etc. Basically non-exotic core renderer functionality. That is what I'm curious to know. I take it for granted that there will be a lot of tweaking required for FG and such.

SI has very little control over what comes out of mental images. SI is only responsible for the implementation: what mr features are exposed and how to use them in the software GUI. There will be as much tweaking for memory and speed is if you were using mr standalone.

That said, there are important issues regarding memory usage. Here are very personal stastistics for XSI 3.5 (might have changed in 4.0 but last time I heard about it, it didn't).
If you render a scene that requires a LOT of memory, you will be subject to constant crashes. This is a XSI limitation. If you render in the XSI GUI, you will crash as soon as the ram use reaches about 850 Mb. If you render the same thing with XSIBatch (the GUI-less version of XSI), you will crash at 1.350-1.4 Gb of ram. But in mr standalone, well, chances are you won't crash at all. I've seen with my own eyes ray3 reaching a staggering 1.8 Gb of ram use without crashing (although Windows normally doesn't allow more than 1.3 for a single process). The implementation of mr might be the best out there of the industry, it is still not perfect.



>>> Hmm, that's no good, I like to comp 3D. I have seen the La Maison post-motion blur shader, this seems like a good solution in many situations. But if you can't get good MB in an acceptable time frame in render passes, then this is a deal breaker for me.

To output motion blur vectors with the 2dmv shader you don't need to calculate motion blur.



>>> I mean depth map shadows...some EI users call them buffer shadows :)

Deep shadow maps are very new, they only appeared in XSI 4.0. I can't tell how good they are, since I haven't used them (at the studio we have our own deep shadow map custom shader).


Cheers
Bernard

thebigMuh
08-21-2004, 09:51 PM
Buffer shadows = Depth Map shadows = Shadow Mapped shadows. This is NOT the same as Atyss meant in his last post, which are Detail shadows = Deep shadow maps = Volumic shadows. There are too many buzzwords in this industry.


Good ole shadow mapped shadows have been around forever. They are really easy to set up in XSI, and since mental ray adaptively renders only those parts of shadow maps that are actually in view, even using point lights with high shadow map resolutions generally won't cause any problems and be quite quick.

Detail shadows are fresh in MR 3.3 / XSI 4.0, and they are the bees knees for stuff like hair. Being really fast and accurate as well as allowing transparent shadows and softness control, they are a hybrid between raytraced shadows and shadow mapped shadows. You'll like them.


Rapid Motion blur is quite a lot faster than standard blur, and can be turned up until all sampling noise vanishes. It works in a way similar to Renderman motion blur.

Ciao, ímuh!

Blur1
08-21-2004, 11:52 PM
theBigMuh, thanks for your opinion on buffer shadows in XSI.

>>>>Rapid Motion blur is quite a lot faster than standard blur, and can be turned up until all sampling noise vanishes. It works in a way similar to Renderman motion blur.

That's exactly what I am interested in, no sampling noise and more like prMan. But what about this alpha problem? Is it easy enough to set up if you want to render an alpha as well, or is that something that will have to wait for an XSI update?

Thanks

Michael

Blur1
08-22-2004, 12:08 AM
>>>>Well, mr for XSI is the same as mr for Maya. It's mr. So you'll find the same challenges in XSI than with Maya. The only difference if the toolset (Render Tree) to work with mr is a lot more developed. But overall it's pretty much the same shaders with the same problems.

Yeah well it's all in the tweaking, so you answered my question when you said that XSI's render tree is a lot more attuned to working with mr.


>>>>That said, there are important issues regarding memory usage. Here are very personal stastistics for XSI 3.5 (might have changed in 4.0 but last time I heard about it, it didn't).

Thanks. That's interesting. As a comparison, it is common to use over 1 GB of ram with Camera. I took that for granted. It just seems from what you are saying that one needs a mr renderfarm. I'm not going to be using it in production, but I do expect to be able to render animations at PAL res and above with one seat of Foundation without having huge problems.


>>>To output motion blur vectors with the 2dmv shader you don't need to calculate motion blur.

I know. I ordered that sentence a bit strangely. What I meant is, even with the La Maison shader as an alternative, I would still expect good motion blur form the renderer.

thebigMuh
08-22-2004, 12:52 AM
I'm not 100% sure what Atyss meant with the alpha problem. I'm not an animator guy, I'm more at home with shaders. There are special considerations for Rapid Motion blur in connection with shader writing, but I guess that's not what he meant.

I did a quick test pic for you. Just a bunch of rainbow colored cubes falling down and bouncing off an (invisible) plane. Shutter speed was 10 frames. This was done using the rapid motion blur mode. As you can see, curved motion also works nicely (I used 8 steps here). I wouldn't want to wait for that with normal temporal sampling mblur:

http://img59.exs.cx/img59/9422/ExtremeMBlur.jpg

Here is the alpha channel of the very same image:

http://img59.exs.cx/img59/9828/ExtremeMBlur_alpha.jpg

With all of that said, shader writing isn't rocket surgery ;)

Also, XSI has a very very nice set of base shaders, more than all other packages I've seen so far offer. They really allow you to take advantage of mental ray (I'm thinking of a lot of the simple mathematics shader stuff here).

Ciao, ímuh!

Blur1
08-22-2004, 01:10 AM
Thanks for posting the example! It looks great. It's not perfect, but much better than what I've seen in the past. And the alpha looks fine! How long did it take to render that frame? Also, with the rapid motion blur do you know if it's possible to render rgb that is not premultiplied with the alpha channel? Meaning "straight" or "unmatted" rgb.

Michael

thebigMuh
08-22-2004, 01:26 AM
Producing unpremultiplied output is just a matter of unticking a checkbox in the render options.

The frame took 3 minutes to render at the resolution you see here.

The settings are way too high for animation rendering however.

Ciao, ímuh!

Blur1
08-22-2004, 04:53 AM
Glad it's just a checkbox for the unpremultiplied output. So if that was 3 minutes a frame with such a wide open shutter, and at over 1K res, I guess render speed would be good for more normal motion blur settings.

Cheers,

Michael

Atyss
08-22-2004, 02:15 PM
I'm not 100% sure what Atyss meant with the alpha problem. I'm not an animator guy, I'm more at home with shaders. There are special considerations for Rapid Motion blur in connection with shader writing, but I guess that's not what he meant. Perhaps I have chosen the wrong words.

Do this simple test:

CreatePrim("Sphere", "NurbsSurface", null, null);
SIDuplicate("sphere", 1, siUnspecified, null, 0, null, null, null, null, null);
CutObj("sphere1");
SetValue("sphere1.kine.posX", 7.69902912621359, null);
SetValue("sphere1.kine.posY", 0, null);
SetValue("sphere1.kine.posZ", 0.622236095936124, null);
ActivateObjectSelTool(null);
ActivateObjectSelTool(null);
ActivateObjectSelTool(null);
ActivateObjectSelTool(null);
SetAndToggleSelection("sphere1", null, true);
ActivateObjectSelTool(null);
Translate(null, -12.8634796615915, 4.60457398725062E-16, -7.52008834982492, siRelative, siView, siObj, siXYZ, null, null, null, null, null, null, null, null, null, 0);
ActivateObjectSelTool(null);
SetAndToggleSelection("sphere", null, true);
ActivateObjectSelTool(null);
ApplyShader("Material\\Constant", "", null, "", siLetLocalMaterialsOverlap);
SetValue("sphere.Material.Constant.color.red", 0, null);
SetValue("sphere.Material.Constant.color.green", 0, null);
SetValue("sphere.Material.Constant.color.blue", 0, null);
SetValue("sphere.Material.Constant.color.alpha", 0, null);
ActivateObjectSelTool(null);
SetAndToggleSelection("sphere1", null, true);
ActivateObjectSelTool(null);
ApplyShader(null, "", null, "", siLetLocalMaterialsOverlap);
InspectObj("Scene_Root.AmbientLighting", "", null, 1, null);
SetValue("Scene_Root.AmbientLighting.ambience.red", 0, null);
SetValue("Scene_Root.AmbientLighting.ambience.green", 0, null);
SetValue("Scene_Root.AmbientLighting.ambience.blue", 0, null);
InspectObj("ViewRenderOptions", "", null, 1, null);


Then draw a render region. You'll see that the front sphere will cut out the back sphere, both in a rgb in alpha. Then set the scanline type to Rapid Motion. No more cut out, and the back sphere even becomes faceted.

This is quite a serious issue, because you will need to rewrite shaders to workaround that problem.


Cheers
Bernard

thebigMuh
08-22-2004, 10:19 PM
Ah, that's what you meant.

That can be remedied with a simple pass-through shader, though.

*hobbles off to compiler*

Ciao, ímuh!

JDex
08-22-2004, 10:49 PM
Ah, that's what you meant.

That can be remedied with a simple pass-through shader, though.

*hobbles off to compiler*

Ciao, ímuh!
Gigity-gigity-goo - Get-her-done!

The muh is on the case.

bravmm
08-23-2004, 10:15 AM
LOL !!
Go iMuh! go...:bounce:

cheers,

rob

thebigMuh
09-12-2004, 03:24 AM
Here's that shader:

http://animus.brinkster.net/downloads/OpacitySet.zip

Sorry that it took so long ;)

No documentation or stuff, it's pretty straightforward.

Ciao, ímuh!

wurp
09-12-2004, 10:40 AM
I also had tons of problems with this bloody rapid motion transparency/alpha issue. Why should we have to go through all this workaround b-shit to create something as basic as mattes, which has been done since the dawn of 3d.... all I can say is POO ON JOO MI!

Fluckrat
09-12-2004, 03:01 PM
Nice one Muh, cheers :)

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