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# 16 27-05-2012 , 06:37 PM

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If you get displacement to work on a transparency map please share how you did it. I tried for a day and could not get it to work.

Also, displacement will create geometry so in the end you'll have as heavy a mesh as if you had modeled the net. But I'd still like to know if transparency plus displacement can work. I tried it on the grating for creckz tank but could not get it to work and although it looked okay at a distance up close it is clear that it has no thickness.

"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

Last edited by ctbram; 27-05-2012 at 06:44 PM.

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# 17 27-05-2012 , 08:06 PM

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Thanks Jay not used Z for a while now be trying the texture route getting some success, Rick the transparencey seams to work for me all I did was plug it into the transparencey of a blinn did forget to do the alpha thing first but ticked that and it worked, were you trying with a occlusion render, still some work to do..............dave

Edit:you are wright about the poly count Rick but my system runs better in view port using a displacement

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Last edited by daverave; 27-05-2012 at 08:26 PM.

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# 18 27-05-2012 , 08:46 PM

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The transparency map looks good Dave. Is that both transparency and displacement? It looks like it has thickness. If it is can you please explain how you got it to work? I tried both transparency and displacement but could not get it to work!

As I look closer it could just be good texturing giving the appearance of thickness. In any event that looks pretty good.

"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

Last edited by ctbram; 27-05-2012 at 08:48 PM.

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# 19 27-05-2012 , 09:08 PM

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Rick it is a displacement map with transparencey there is a link to how I made the displacement and like I said I did nothing that great to do the transparencey, I can see some problems with this but I think this is more to do with the lighting.............dave

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# 20 27-05-2012 , 09:12 PM

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Could you please make a video of how you did this with transparency?

I know how to do both individually so your reference link does not teach me anything I don't already know.

I want to see how you are getting both transparency and displacement working on that net. I tried to do it with a grating but could not get both transparency and displacement working so I would really like to see how you are achieving it.

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# 21 27-05-2012 , 09:26 PM

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Dave, here is an tileable alpha mask for the grating I was trying to make using both transparency and displacement. I could get the transparency to work but not the displacement.

Could you use this and make a camtasia vid on how to create a grill using this alpha plus displacement please. I will add it to my HOWTO library for when I might need it again and of course will have totally forgotten how to make it work. lol

Thanks!

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# 22 27-05-2012 , 09:35 PM

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I dont mind giving it a go Rick but I did try doing this when you were and had bad result using normal maps, I think it was the size of the texture you need to think big say 2k to start with give me a few days to try to make it work then I will let you know if I can do it.............dave

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# 23 27-05-2012 , 10:28 PM

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Thanks Dave,

I still have a lot of problems with normal maps. But this is something different. I want to apply the transparency map to create a grill and then displacement to give it thickness. I'll record up the process I tried so you can see the issues I am having and how I am trying to do it.

-Rick

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# 24 27-05-2012 , 10:34 PM

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you'll have dispalcement issues with the mesh being paper thin at the edges so unless you add geo to it and feather/fade it in at the edges, you'll have probs when it renders

Jay

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# 25 28-05-2012 , 12:31 AM

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yes Jay that is why I am asking Dave to show how he managed to add displacement to the alpha map of his netting. I am including the .ma of the grill that I attempted to add displacement to without success.

I do not know how to add geometry to an alpha map short of literally modeling the grill, which I have also done. But being able to use alpha + displacement has a lot of applications and I would really like to understand how to do it.

Mental ray is ridiculous to try and learn and I really get pissed off when I try to figure things out! There is practically no usable documentation on anything. The documentation that does exist is like reading stereo instructions written in Latin and converted to English by a French person that only reads Dutch!

There are thirty five million buttons and dials and switched that are scattered all over the maya interface and all affect one another and no documentation on any reasonable workflow for the proper way to adjust them. Some knobs you twist in a range from 0 to 50 billion and it has no affect and the next noob if you tweak it from 0 to .000001 you've gone outside the acceptable range! It's just maddening!

"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

Last edited by ctbram; 28-05-2012 at 01:05 AM.

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# 26 28-05-2012 , 12:41 AM

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Dave, here is the .ma of the grill I was working on and a link to the video that describes it. I thought I would give you the actual file and all the textures so I could see how to apply the displacement to the model that I was unsuccessful with.

https://youtu.be/iOfO24tz7fE

hmmm, crap it appears the largest .zip I can include is 1MB and because of the images the folder, even zipped, is 15MB. I will need to figure another way to put it someplace you can download it from.

"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

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# 27 28-05-2012 , 12:53 AM

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Okay, I cleaned out the large image files and it's now just a little over 1MB.

Here is a link to my public dropbox folder....

https://dl.dropbox.com/u/5501128/howt...y_and_disp.zip

I think I deleted the .png for the alpha and included the .jpg. So when you go to the hypershade you can point to the .jpg instead.

-Rick

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Last edited by ctbram; 28-05-2012 at 01:02 AM.

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# 28 28-05-2012 , 06:23 AM

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Here is a video of how I tried to apply the displacement map and the bad result I got plus nearly 8 minute render times (. If anyone can spot what I am doing wrong please chime in.

https://youtu.be/S7uytQ0kKJE

For both maya software and mental ray displacement I do the following things...

1. middle mouse drag the displacement texture in the SG node displacement field

2. control disp height by adjusting the alpha gain in the color balance tab of the disp texture

3. Control the disp bounding box in the shape nodes displacement drop down

The following is required for mental ray to control the quality of the disp tesselation

4. create a mental ray approximation displacement tessellation node for the surface being displaced. I choose the spatial method and pick a max triangle edge length based on my scene units and the surface being tessellated.

NOTE: for maya software render displacement tessellation quality is controlled with the feature displacement tab of the shape node "initial sample rate" and "extra sample rate" settings. This is ignored for mental ray renders. But it is important to note the bounding box setting is used for both mental ray and maya software renders so alway compute the bounding box after changing the color balance alpha gain.

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# 29 28-05-2012 , 10:25 AM

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Sorry for not getting back to you Rick my bed time, looks like you sorted out the transparencey.You know a lot more about displacements then me, I am hiding any distortions in the colour map. I wish there was a volume shader for things like this...............dave

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# 30 28-05-2012 , 10:28 AM

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yeah I agree with you here Dave. I see that mental ray has volume shaders but they do not do what I think we are looking for.

I saw a very interesting vray demo where they add thickness (displacement) to a transparency map and like all things NOT MENTAL RAY it looked very intuitive. I will try to find the link for you. They model a car engine and then add raised text and a raised hex pattern using displacement and it looks perfect and there are like 3 steps and one knob to twist (how much displacement do you want?) none of this trying to figure out the displacement tessellation, and bounding box, and adjusting values in multiple nodes crap!

BTW have you tried to convert the displacement of your net to polygons? I tried on my grill and got a single poly plane and it was a mess with no holes at all. Like it ignored the transparency. I get really annoyed at stuff in maya that is really over complicated, buggy, or just plane does not work. it's frustrating to blow hours and sometimes days or weeks only to find you cannot get from point A to point B in maya or mental ray.

It should not be this big a chore to take something and add thickness to it! It's been a requirement for ages and I do not see why it has to be such a chore in maya or mental ray. I saw displacement tutorials to do this exact thing in lightwave, modo, and maya (using vray 2.0 RT) and they all seemed to be very intuitive compared to this convoluted workflow that ends up with crappy results in Maya and mental ray.

"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

Last edited by ctbram; 28-05-2012 at 11:08 AM.

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