I'm rendering a scene in Maya using Mental Ray, (not using the CMD line, had some problems in the past, would love some help with that as well). it's a really simple scene with a single object and single shader. i have a series of color blender utilities that are keyed to basically cycle through 6 color's. the project is just making some psychadellic imagery that will be used as Eye candy. The problem is that wherever i start the batch render it keeps that color and doesn't blend, even though it does in test renders and the real time view. I think the problem lies within the way that the texture data is cached but i'm not sure. thanks for the help guys
this had no effect. it stays the same color as the first rendered image. Ie. at frame 1 it's red. and any render starting on frame one will stay red the whole time. however, if i start the render at frame 600 hundred the the object is shaded blue and will continue to be shaded blue for the whole batch.
How is your shader network set up? You have to realize that theres no GUI behavior in batch ender thus niothing thet fo ces certain types of nodes to update.
This has severe effects on mentalray because its NOT reading maya nodes. It is in essence only doing a small subset of nodes, rest is asks maya to do upfront. However if something is in between a time compute and a up front querry it might not do that.
The most problematic of all of these are expressions, wich are quite efficient but easy to abuse, and a abused expression is a horror on your batch render because it does just not see it at all in worst case scenario. Its not a bug or dad design, its freedon of choice. Your free to screw everything up if you want to, but f you do then your the one wwho has to work it all out too.
i have zero expressions right now but i have a ball controlling set driven keys, ie. i animated the ball cycling from -3 to 3 and at each whole number the color blend utilities are keyed to switch. here's a pic of my workspace in the hypershade
Please if anyone can, help me.... :') typically i'm a modeller who doesn't do much rendering, but I'm now the 3d generalist for a very small company and would love some feedback from the masters here at highend..... any input is REALLY appreciated, thanks Kobayashy for your advice, even though it didn't work I'm glad someone responded and of course thank you JooJaa, I hope to eventually be capable of following all of your explanations. I simply need more knowledge of how this all works....
so are you saying that the sdk on a utility will not work in mental ray or what? the set driven keys are made of a ball and it's translate Y as the driver and the blender node in the blend color utilities as the driven. it's not very complicated but is there a way to do this so that mental ray will recognize the utilities or, if i have to, is ther a way to do this with using the MR textures?
No im saying anim curves dont export as dynamic in older mayas. Buut this does not apply to 8.5. Anyway as said i cant replaicate this so the problem is upstreams.
this is basic stuff so you should make effort to really understand this (if you dont then be prepared to have this probklem every second time you do stuff):
this is how it works with mentalray, maya prepares the scene for mentalray to take in the scene. Maya pre computes its own state and then makes a STATIC export of this set into mentalray (imagine if you will that your animation is sliced to many snapshots of one mesh each frame). Because shading nodes act on the data by varying each point maya cant precompute this step. But instead maya has a library of corresponding, but NOT same, mentalray nodes. Therese nodes then do all the varying computation. HOWEVER only shading nodes and few select other ndoe are exported, blend shapes etc etc are not their value is written to the network as static values.
Now to make things harder to understand theres 2 kinds of mayas (thank god for that), the ones you run and the ones that somebody else runs. This usually trows people who dont think about computation off. Now batch is a different maya form the one you see on screen, it is quite literary a maya that does not have a screen. Also it opens the scene independent of you. Now this means that the animation is evaluated differently form what you have on screen. As theres NOTHING to trigger gui events. So all your data must conform to the way maya evaluates the DG or you'll in trouble. Sure you can do cool stuff with things like this but you should separate the making of things form doing them. Now since this maya is doing the export its UNAVARE of any hacks you have on top of the gui.
SECOND basic thing: theres no such thing a s set driven key theres just a gui that fools you into thinking there is. Theres just anim curves!
PS: im a bit busy so i havent got time to illustrate the facts.
I'm not talking about blend shapes... I'm referring to "color blend utilities." these are the utilities in the shading network that changes the color attribute in the material attached to the mesh. Shouldn't the animation curve of the ball object (the driver of the Color blend utilities) drive the color attribute of the shader? Is there a mental ray shading node with similar effects as the color blend utility?
Ok i couldnt replicate the problem on my machine like i said it works fine for me BUT i can replicate it on my backup laptop thet runs PLE (i had a crah on my main laptop yesterday, which doesnt have a service pack, or any of my 20000 or soe lines of unnormal code on top):
QUOTE I'm not talking about blend shapes...
Neither am i i just took a exaple much furter away form home so you can think in peace. etc etc means theres LOTS of such nodes the full list is below:
QUOTE(Woz @ 02/08/08, 02:26 AM) [snapback]280804[/snapback] Shouldn't the animation curve of the ball object (the driver of the Color blend utilities) drive the color attribute of the shader? Is there a mental ray shading node with similar effects as the color blend utility?
No, the ball isnt a shading node neither are the anim curves connected out form it (maya thinks they are the end of the line). Try baking the outputs of the graph curves in your prerender script. This forces it to update them
Whats happening is very well described in the previous post.
*the quicklyt filtered list of nodes to replace by blrendshape in above post:'
