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http://cgarthub.com/index.php?topic=69.0
1. DON`T USE TOO MANY LIGHT BOUNCES
usually first diffuse bounce is enough, you may try with one more secondary bounce, but not more... (for simple building, without many carved - semi-interior spaces) [render options -> GI settings]
2. DON'T USE TOO HIGH IRRADIANCE SETTINGS FOR RENDERING HUGE IMAGES
for image size of ~3600 pixels use irradiance settings like: min/max=-4;-3 (="very low" preset) with interp. samples=25 (to make things more smooth), or for the "superb" quality min/max=-4;-2"
3. ALWAYS SAVE YOUR IRRADIANCE MAP
may be useful to re-use it, when you'll be making some alterations to the image (incremental add is also useful then)
4. IF YOU HAVE A LOT OF RAM
you can speed things up by tweaking the vray system raycaster params. go up to 85(max tree depth) and down to 0,5 (face/level coef). but if your rendering doesn`t fit in your physical RAM memory, and gets swapped to the hard drive - then it`s no good - you'll have to lower these settings to the default -> 60;2 or even lower values, like 50;4.
5. DON`T ANTIALIAS TOO MUCH
for a huge images (as 3600 pix) it`s a good choice to set antialiasing to adaptive -1;2 with a tolerance of ~0,12. however some say that when using lots of fuzzy effects (like area shadows and glossiness) antialiasing mode should be switched to a fixed value or simple two level. from my experience in arch. renderings the adaptive mode works best in any case.
6. DON`T USE TOO MANY REFLECTION/TRANSPARENCY LEVELS
make it 2-3 max. this in most cases is enough [render options -> global switches]
7. SWITCH OFF THE "REFLECT ON BACKSIDE" PARAMETER
it slows things down generally and doesn`t have a great impact on the final look [in material editor -> vraymap/vray material]
8. REMEMBER ABOUT INTERPOLATED GLOSSIES
they take some time to render, but bring a lot of life to a huge flat, boring elevations and, of course, render a lot faster than direct computed glossies [material editor -> vray material -> reflection -> use interpolation -> reflect interpolation settings = -3;-1 or, for better "sharp" precision leave them at their default]
9. USING BUMP MAPS TOGETHER WITH INTERPOLATED GLOSSIES IS PAINFUL
and usually it produces lots of noises - try to avoid it
10. IF 3600pix IMAGE IS JUST TOO MUCH FOR YOUR MACHINE
make it 1600 or 2200pix and resize it to 3600 in PS/PP applying some directional sharpen. or try resizing it in program such as ssplinepro. no-one will notice )) ... until it`s printed on a laser printer ;(
Logged
arun
Jr. Member
Posts: 67
Re: Ten tips to make your vray renders faster
« Reply #1 on: August 01, 2011, 08:30:52 am »
FEW MORE POINTS THAT WILL HELP YOUR VRAY RENDERS FAST
Global switches
Geometry
* When working with 3rd party CAD data, specifically Autodesk Inventor 3d files imported into Autodesk 3ds Max, leaving displacement ticked increases render times considerably. I assume this is to do with how it reads the mesh data. Obviously you will need to leave this on if you plan to have displacement in your scene, if not, turn it off.
Indirect illumination (GI)
Irradiance map
* This GI method is resolution dependant, so adjust the min/max rate to suit your output resolution.
* If you have multiple camera views for the same scene, save out an incremental irradiance map. The same map can be used providing there is over lapping geometry between camera views. This will save you some rendering time.
* Tick show calc. phase, this will show you the irradiance map as its calculating. After a few seconds you will begin to get an idea of the general illumination of the scene. If it is incorrect you can cancel the render, therefore only wasting a small amount of time.
Light cache
* Tick use light cache for glossy rays, this can reduce rendering times by quite a lot if you have heavy glossy reflections in your scene. Keep in mind that it is very dependent on the scene and because of this, in some instances it can lead to unwanted artefacts. There are multiple steps you can take to avoid this happening.
Option A
If you have the latest version of Vray (which is 2.0), there is an added feature called retrace threshold which improves the precision of the global illumination and helps eliminate light leaks when use light cache for when glossy rays is on.
Option B
Set the filter to fixed and adjust the filter size to two or three times the sample size. So if your sample size is 150 mm set the filter size to 300 mm.
Option C
Within a material, scroll down to the options panel and set treat glossy rays as GI to always. Also turn off the use light cache for glossy rays if you have it on. By doing this you are telling the material to always use the secondary GI engine to calculate the glossy rays, which in this case is the light cache. It basically does the same job as use light cache for glossy rays but you can specify which materials within the scene use this option.
* Use screen as a method for scale when dealing with scenes that have large ground planes and distant objects. If you choose world scale, you may find that these distant objects can become very noisy, and you may decide to increase samples to remove this noise which will lead to longer render times.
* Set your number of passes to the number of processor cores you have in your PC. Even if you have multiple cores over multiple PC’s, the light cache is only calculated on one PC.
Settings
System
* By default, Vray sets the dynamic memory limit to 400, but this can actually go a lot higher. It is recommended to change this to a value that is half your RAM amount. For example if you have 8GB of RAM, you can set this to 4000.
Render elements
* Save out all your passes as separate files to later on composite them in post. This will allow you to tweak each individual aspect of your render such as lighting, reflection, refraction and shadow without the need to re–render the whole image again.
Material editor
Reflect
* When adjusting the reflective glossiness, you will need to increase the subdivs value to compensate, otherwise you will get very noisy results. Do not fall into the habit of setting the subdivs to a value you use throughout your scenes. Setting all your reflective materials to a subdivision of 32 for example, is not a solution. In fact it will increase your render times unnecessarily. Keep in mind that the higher the reflective glossiness, the lower subdivisions you can have. If you have reflective glossiness set to 0.85 you can set your subdivisions to 16 or even lower depending on your set up. If the reflective glossiness is set to 0.6, it would require a higher subdivision. This requires a little experimenting but it is good practice, especially for architectural visualisation, to have a default library of materials that you can use for multiple projects. This way, you won’t have to keep adjusting subdivisions because you know that material from your library is good enough.
Refract
* From experience, adjusting the refraction glossiness does more harm than good unless you are aiming for a frosted effect. If not the majority of results are less than noticeable, and the render times are through the roof. Keep this at 1.0 and leave you subdivs alone. You will save so much render time this way.
It is also important to understand render output resolution and DPI, Make sure you know what’s happening to the render once you have signed it off. If you have rendered an A3 image at 300 DPI and you then later on find out that image was going into a small area on an A5 leaflet, you have rendered your image at a higher resolution than what was required.
http://cgarthub.com/index.php?topic=69.0
1. DON`T USE TOO MANY LIGHT BOUNCES
usually first diffuse bounce is enough, you may try with one more secondary bounce, but not more... (for simple building, without many carved - semi-interior spaces) [render options -> GI settings]
2. DON'T USE TOO HIGH IRRADIANCE SETTINGS FOR RENDERING HUGE IMAGES
for image size of ~3600 pixels use irradiance settings like: min/max=-4;-3 (="very low" preset) with interp. samples=25 (to make things more smooth), or for the "superb" quality min/max=-4;-2"
3. ALWAYS SAVE YOUR IRRADIANCE MAP
may be useful to re-use it, when you'll be making some alterations to the image (incremental add is also useful then)
4. IF YOU HAVE A LOT OF RAM
you can speed things up by tweaking the vray system raycaster params. go up to 85(max tree depth) and down to 0,5 (face/level coef). but if your rendering doesn`t fit in your physical RAM memory, and gets swapped to the hard drive - then it`s no good - you'll have to lower these settings to the default -> 60;2 or even lower values, like 50;4.
5. DON`T ANTIALIAS TOO MUCH
for a huge images (as 3600 pix) it`s a good choice to set antialiasing to adaptive -1;2 with a tolerance of ~0,12. however some say that when using lots of fuzzy effects (like area shadows and glossiness) antialiasing mode should be switched to a fixed value or simple two level. from my experience in arch. renderings the adaptive mode works best in any case.
6. DON`T USE TOO MANY REFLECTION/TRANSPARENCY LEVELS
make it 2-3 max. this in most cases is enough [render options -> global switches]
7. SWITCH OFF THE "REFLECT ON BACKSIDE" PARAMETER
it slows things down generally and doesn`t have a great impact on the final look [in material editor -> vraymap/vray material]
8. REMEMBER ABOUT INTERPOLATED GLOSSIES
they take some time to render, but bring a lot of life to a huge flat, boring elevations and, of course, render a lot faster than direct computed glossies [material editor -> vray material -> reflection -> use interpolation -> reflect interpolation settings = -3;-1 or, for better "sharp" precision leave them at their default]
9. USING BUMP MAPS TOGETHER WITH INTERPOLATED GLOSSIES IS PAINFUL
and usually it produces lots of noises - try to avoid it
10. IF 3600pix IMAGE IS JUST TOO MUCH FOR YOUR MACHINE
make it 1600 or 2200pix and resize it to 3600 in PS/PP applying some directional sharpen. or try resizing it in program such as ssplinepro. no-one will notice )) ... until it`s printed on a laser printer ;(
Logged
arun
Jr. Member
Posts: 67
Re: Ten tips to make your vray renders faster
« Reply #1 on: August 01, 2011, 08:30:52 am »
FEW MORE POINTS THAT WILL HELP YOUR VRAY RENDERS FAST
Global switches
Geometry
* When working with 3rd party CAD data, specifically Autodesk Inventor 3d files imported into Autodesk 3ds Max, leaving displacement ticked increases render times considerably. I assume this is to do with how it reads the mesh data. Obviously you will need to leave this on if you plan to have displacement in your scene, if not, turn it off.
Indirect illumination (GI)
Irradiance map
* This GI method is resolution dependant, so adjust the min/max rate to suit your output resolution.
* If you have multiple camera views for the same scene, save out an incremental irradiance map. The same map can be used providing there is over lapping geometry between camera views. This will save you some rendering time.
* Tick show calc. phase, this will show you the irradiance map as its calculating. After a few seconds you will begin to get an idea of the general illumination of the scene. If it is incorrect you can cancel the render, therefore only wasting a small amount of time.
Light cache
* Tick use light cache for glossy rays, this can reduce rendering times by quite a lot if you have heavy glossy reflections in your scene. Keep in mind that it is very dependent on the scene and because of this, in some instances it can lead to unwanted artefacts. There are multiple steps you can take to avoid this happening.
Option A
If you have the latest version of Vray (which is 2.0), there is an added feature called retrace threshold which improves the precision of the global illumination and helps eliminate light leaks when use light cache for when glossy rays is on.
Option B
Set the filter to fixed and adjust the filter size to two or three times the sample size. So if your sample size is 150 mm set the filter size to 300 mm.
Option C
Within a material, scroll down to the options panel and set treat glossy rays as GI to always. Also turn off the use light cache for glossy rays if you have it on. By doing this you are telling the material to always use the secondary GI engine to calculate the glossy rays, which in this case is the light cache. It basically does the same job as use light cache for glossy rays but you can specify which materials within the scene use this option.
* Use screen as a method for scale when dealing with scenes that have large ground planes and distant objects. If you choose world scale, you may find that these distant objects can become very noisy, and you may decide to increase samples to remove this noise which will lead to longer render times.
* Set your number of passes to the number of processor cores you have in your PC. Even if you have multiple cores over multiple PC’s, the light cache is only calculated on one PC.
Settings
System
* By default, Vray sets the dynamic memory limit to 400, but this can actually go a lot higher. It is recommended to change this to a value that is half your RAM amount. For example if you have 8GB of RAM, you can set this to 4000.
Render elements
* Save out all your passes as separate files to later on composite them in post. This will allow you to tweak each individual aspect of your render such as lighting, reflection, refraction and shadow without the need to re–render the whole image again.
Material editor
Reflect
* When adjusting the reflective glossiness, you will need to increase the subdivs value to compensate, otherwise you will get very noisy results. Do not fall into the habit of setting the subdivs to a value you use throughout your scenes. Setting all your reflective materials to a subdivision of 32 for example, is not a solution. In fact it will increase your render times unnecessarily. Keep in mind that the higher the reflective glossiness, the lower subdivisions you can have. If you have reflective glossiness set to 0.85 you can set your subdivisions to 16 or even lower depending on your set up. If the reflective glossiness is set to 0.6, it would require a higher subdivision. This requires a little experimenting but it is good practice, especially for architectural visualisation, to have a default library of materials that you can use for multiple projects. This way, you won’t have to keep adjusting subdivisions because you know that material from your library is good enough.
Refract
* From experience, adjusting the refraction glossiness does more harm than good unless you are aiming for a frosted effect. If not the majority of results are less than noticeable, and the render times are through the roof. Keep this at 1.0 and leave you subdivs alone. You will save so much render time this way.
It is also important to understand render output resolution and DPI, Make sure you know what’s happening to the render once you have signed it off. If you have rendered an A3 image at 300 DPI and you then later on find out that image was going into a small area on an A5 leaflet, you have rendered your image at a higher resolution than what was required.
