Reflection Attenuation

[Mzigaib]

How can I make my reflection falloff on distance?

I have a control for attenuation density for interior color, but not for reflection.

Edited June 11, 2010 by Mzigaib

[Mzigaib]

No one? isn't there a way to make my reflection fade according to distance?

[petz]

quick example file attached!

petz

reflection.hipnc

[Mzigaib]

Thank you very much for the file, that´s exactly the result what I was looking for.

But isn't there a way to achieve this result through VOP nodes without having to write a code? I am just asking that because I know very little about shading writing and I was wondering if I could do it myself without have to write any code.

Again I really appreciate the help that you gave me and I know that learning hoe to write would be part of the job, but it doesn't hurt to ask.

Cheers!

[petz]

Thank you very much for the file, that´s exactly the result what I was looking for.

But isn't there a way to achieve this result through VOP nodes without having to write a code? I am just asking that because I know very little about shading writing and I was wondering if I could do it myself without have to write any code.

Again I really appreciate the help that you gave me and I know that learning hoe to write would be part of the job, but it doesn't hurt to ask.

Cheers!

same in vops.

hth.

petz

reflection_vops.hipnc

[Mzigaib]

Thanks you very much, this will really help, though this one seems more complicated than the one with the inline code.

Can you give an advice where can I start to learn vex shader writing?

Again thanks for the help.

[Mzigaib]

Hi, it's me again.

Isn't there a way to make this effect on the reflective material on houdini gallery? There I have all the things that I need I just need to add this effect, I tried to use your vops on it but I wasn't successful,I was thinking in a way just to modify the nodes before the reflect VOP inside the reflective material but my knowlege is limited to do it.

Anyway thanks for the help.

[Mzigaib]

same in vops.

hth.

petz

Even being a newbie on making shaders, I did get to do what I wanted with your code even don't understanding all of it, using it to just modify the reflective material, so I would like to know what you think since you helped me to build it.

But if theres a better or simpler way to do it let me know.

Thanks again.

reflectiveAttenuation.hipnc

[petz]

Even being a newbie on making shaders, I did get to do what I wanted with your code even don't understanding all of it, using it to just modify the reflective material, so I would like to know what you think since you helped me to build it.

But if theres a better or simpler way to do it let me know.

Thanks again.

in your example you are using gather() for measuring the raylength and the trace-vop for the reflection. since the trace-vop internally also uses gather() you force mantra to do the same job twice. to avoid this overhead you can do two things:

- replace the trace-vop completely by the gather-vop or use gather() inside an inline-vop for computing the reflection and raylength

- modify outer and inner code of voplib.h under $HH/vex/include and the trace-vop so that the raylength will be returned. but i would suggest to let the header files untouched exept you know exactly what you are doing.

assumed you don´t need glossy aka. blurry reflections it´s easy. rayhittest() or the rayhit-vop returns the raylength which you can use for the reflection-falloff.

hth.

petz

Edited June 18, 2010 by petz

[Mzigaib]

- replace the trace-vop completely by the gather-vop or use gather() inside an inline-vop for computing the reflection and raylength

- modify outer and inner code of voplib.h under $HH/vex/include and the trace-vop so that the raylength will be returned.

If I just replace The Trace-Vop for the Gather-Vop will it do the trick? I am asking this because replacing codes it's too advanced for me at the moment.

But anyway thanks for the tip.

[Mzigaib]

Is there a way to to do the same thing that you did with the gather vop but instead use the trace vop?

Edited June 18, 2010 by Mzigaib

[Mzigaib]

I think I got it!

See what you think about my try to use trace vop and rayhit to add falloff to my reflection.

Now I got what you meant about the blurry reflections, with this technique I can´t use it, if I want it in conjunction with reflection falloff the gather vop is the only way right?

Since I am using the gather VOP I would like to add all the features that the trace vop has for reflections, so I didn't figure out how to put jitter and the backgound color options, any tips would be nice.

Anyway thanks again.

reflex_falloff_with_trace_vop.hipnc

Edited June 30, 2010 by Mzigaib

[petz]

I think I got it!

See what you think about my try to use trace vop and rayhit to add falloff to my reflection.

Now I got what you meant about the blurry reflections, with this technique I can´t use it, if I want it in conjunction with reflection falloff the gather vop is the only way right?

Since I am using the gather VOP I would like to add all the features that the trace vop has for reflections, so I didn't figure out how to put jitter and the backgound color options, any tips would be nice.

Anyway thanks again.

you are on the right track! attached is a file with a modified trace-vop that should do what you want. its coded but it shouldn´t be too hard rebuilding it with vops.

btw. dont forget to load the otl

trace_refl_falloff.rar

[Mzigaib]

Man I can´t thank enough for the help

Your otl would give me just what I want, what I need now it´s just to understand how it works for learning purposes.

My Code skills are still in the very beginning in fact until now I just worked with the Visual Vex which is awesome, I also need to study more about the gather VOP, which by what I saw that it can give you a great amount of freedom to build cool stuff with reflection rays maybe more.

Man, I really feel a little ashamed to ask but if isn't much trouble would be really great to have your OTL coded on VOPs.

Anyway thank you very much for the help.