Some lighting help please

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Old 12 December 2012   #1
Flickering/ buzzing textures on static objects (camera animated)

Hello,

I have not done much Maya work in years so please excuse the possible rudimentary nature of this question with all the great talent here it may seem rather newbie!

I have to do a rather straight forward cam fly around of a master-planned community. I set up a quick test scene to get the basic lighting blocked it. I used automated lights and standard lights and I am not really thrilled about the lighting but my larger issue is that I am getting unexpected and undesired effects happening.

I will link to two images to illustrate the two issues I am having-firstly you will see some lines in the textures causing almost cross hatching or diamonds (I have indicated these).
Second, the objects, though only textured with simple lambert base shaders, seem to have this sort of burned or dirty look to them. I am curious if this is just bad lighting job or some other setting I am missing?

I am ok if the answer is just I am a crappy lighter if it comes with a tip or two
Thanks!

Last edited by MB07 : 12 December 2012 at 05:15 PM.
 
Old 12 December 2012   #2
I don't see any links?

Also what renderer are you using and what do you mean by automated lights?
 
Old 12 December 2012   #3
Hello Kyron,

Thank you for your reply and for pointing out the links were missing I must have forgot something there. I am not able to post links from here but will when I get to my PC so hopefully you are still interested in helping me

What I have discovered is that these strange shapes and lines are actually the shadows being cast by imported geos (obj's and fxb's). When I turn off the shadows they do not show anything odd in the render but I would like them on.

Have you encountered this and is there a work around? I do not have the time to rebuild these models even though geos created in Maya are rendering shadows just fine.

I am using just Maya software-I am kinda rusty in Maya rendering and need to turn this project around quick so I do not want to get into Mental ray if I do not have to because physical lighting in Maya is blowing out all my detail.

The automated lights were from a python script I dl'd which was suppose to set up an environment but I created all new lights and the prob remained and ultimately I discovered it was these cast shadows.
 
Old 12 December 2012   #4
I donīt think I can be of much help here. Been ages since I played around with software.

Have you tried switching between depth map and raytraced shadows?
 
Old 12 December 2012   #5
I am unable to see your images but I think those shadow artifacts are because you might be using raytrace shadows and your samples are low try increasing them.
If you are using depthmap then try to fit your model inside the cone angle and increase map size a bit usually 1024 is more than sufficient.
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Old 12 December 2012   #6
Thanks both,

I have shadows appear fine with these objects when using raytracing/ Mental Ray so I guess using depth map shads was what was wrong-not that this should be wrong but it was causing me issues since I didn't adjust any settings or it was just the aforementioned imported geometry issue.

I am not very savvy at rendering but I have managed to make the scene look ok. My textures are being blown out by mia-physical sun but I have read that is corrected by an adjustment setting on the object or shader. I am also getting bad movement on grass and asphalt textures thru Mental Ray-maybe I can direct to a clip later and you can continue to advise me
 
Old 12 December 2012   #7
I alluded to a texture issue and here is that explanation:

My habit has been to use texture files applied to default shader materials and in some cases bump maps. Generally I either use a default fractal bump or I use the same image as the texture file but in grey and with contrast adjusted. I only adjust the UV repeats in the placement settings until I get a look that is ok. I am talking things like grass or asphalt-not textures that need careful placement.

In Sketchup for instance I can do roughly the same thing and the textures give no problems with and animated camera but in Maya they flicker, buzz, look like TV static-whatever you want to think of it as-when the camera moves.

This also happened when I used a grass shader I downloaded. I am using Mental Ray but this occurs with Maya software as well. I am not sure if this is because of my rudimentary way of applying textures or what. I imagine there are better ways to apply textures but I just want to spread out a grass texture like a carpet. Can someone suggest a solution or tutorial that will help me understand this issue relatively quickly as I have a quick turn around on this project.

This seems to be a common problem and solutions vary from deleting history, to changing projection settings to baking textures. Not sure which rabbit hole to go down. :(

Thanks!

Last edited by MB07 : 12 December 2012 at 05:57 PM.
 
Old 12 December 2012   #8
1. Create a File Texture node, or drag-and-drop your file texture into Hypershade.
2. From this node, pick the proper grass texture (tilable, hopefully) you'd like to use.
3. Link your grass Texture node you just made to your Material/Shader's color slot, bump slot, or wherever you need it to go.
4. If you need to spread the tilable texture out, go to your File Texture node's "place2dTexture" node and alter the "Repeat UV" numbers.


But I think you understand all this already? If you could post some images of what your problem looks like, it would really help us help you. Use ImageShack.com or something if you need to?
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Old 12 December 2012   #9
Originally Posted by InfernalDarkness: 1. Create a File Texture node, or drag-and-drop your file texture into Hypershade.
2. From this node, pick the proper grass texture (tilable, hopefully) you'd like to use.
3. Link your grass Texture node you just made to your Material/Shader's color slot, bump slot, or wherever you need it to go.
4. If you need to spread the tilable texture out, go to your File Texture node's "place2dTexture" node and alter the "Repeat UV" numbers.


But I think you understand all this already? If you could post some images of what your problem looks like, it would really help us help you. Use ImageShack.com or something if you need to?


Hey thanks-yeah thats pretty much what I do-sometimes textures work this way but it seems like when you animate the cam it causes the buzzing-I am testing a render where the objects move instead to see if this also happens

http://i1290.photobucket.com/albums...zps87bcdb1c.jpg

Here is the image-I know it was blown out that was before I gamma corrected-but I knida like it haha
 
Old 12 December 2012   #10
I've never had this "buzzing" happen, I guess. I'm not even sure I know what you mean. We really would need some render examples or screenshots to understand your problem. I don't see anything weird about the image you just shared.
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Old 01 January 2013   #11
K when I try to make a clip the compression neccessary to upload is making the issue seem like it is being caused by that. There is probably a better way to do this but I cannot think of it...here are 4 images which you can view using a frame cycler or even just click thru with Windows image viewer and you will see what I am talking about on the roofs.

Again this is just a lambert with a file link to a stuccor texture image. I did the same thing with a grass image on the ground and you can see that it is fine.

I am just not sure why this happens-I do not know much about texturing in Maya so I am unsure if this is because my quick slap on a texture method is too rudimentary or what?
s.


Last edited by MB07 : 01 January 2013 at 07:24 PM.
 
Old 01 January 2013   #12
Still looks like a shadow issue, like everyone else suggested.

- make sure you switch to raytrace shadow on your light.
- also make sure you increase the anti-aliasing quality in your render globals and turn on raytracing.
- I don't think this matters, but try increase the shadow ray under your light's raytrace shadow attributes.
 
Old 01 January 2013   #13
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