Is Irradiance Point Cloud Alright For Animation

Introduction

Global illumination often changes slowly over surfaces. This ways that several neighboring pixels could share similar GI lighting without visible artifacts. This, in turn, ways we don't necessarily have to individually compute GI lighting for each pixel on the screen. Irradiance caching takes reward of this observation and computes GI at sparse points around the image. As a upshot, rendering takes much less time.

These individual GI points are called "Irradiance Cache Points" and are using during rendering (through interpolation and filtering) to produce a polish, concluding result. The figures below show how Irradiance Caching works.

During the irradiance cache computation pass, points are stored on surfaces visible by the camera. On flat areas, lighting changes slowly so few points are needed. Corners typically demand more points.

During rendering, terminal shaded pixels (white) are GI-lit using the previously constructed irradiance enshroud points. That is much faster than computing GI for each individual pixel.

The Irradiance Cache tin only be used as a principal GI engine. When multiple GI bounces are needed, the Irradiance Cache can be combined with:

The Animal-Force secondary GI engine
The Photon Mapping secondary GI engine
The Irradiance Point Deject secondary GI engine

The Irradiance Enshroud has several benefits:

It tin produce smooth images several times faster than Animate being-Forcefulness
The results tin exist saved to disk for each animation frame. So if you're tweaking things like antialiasing, glossy "num rays", expanse lighting "num samples" and other quality parameters (non-related to GI), you can merely load the GI results and perform quick iterations.
Certain scenes (similar archviz ones) utilize relatively apartment geometry. For example, the floor or the walls of an architectural interior. The irradiance cache can provide a significant performance do good for such scenes.
Increasing the concluding paradigm resolution ofttimes does non increase the irradiance cache time linearly. I.e. going from 1280x720 to 2560x1400 (i.due east. 4 times more pixels), you might find the irradiance cache processing fourth dimension taking less than 4 times longer. This depends on the scene complexity and the irradiance enshroud settings.

The Irradiance Cache has some limitations too:

Irradiance Cache Points are computed during a separate rendering pass and so interactive feedback isn't possible.
While a low number of rays shows up as grain in brute-force GI, a depression number of rays shows upwardly as "splotches" and flickering in animations with irradiance cache. These artifacts can exist more visually distracting than grain.
There are several user parameters that command point spacing and the overall quality. Proper configuration of these is important for splotch-gratuitous and flicker-free results. Learning how to apply these settings will involve some trial-and-error.
If the scene contains a lot of geometric particular (example: foliage covering a big part of the screen), too many irradiance enshroud points might have to be generated. This cancels the benefits of the irradiance enshroud algorithm and, even worse, places a brunt on GPU retentivity resource considering of the many points which volition accept to exist stored. For these scenes, creature-strength might exist a better pick. Thankfully Redshift contains a "force-animal-force" per-object option so that such problematic objects tin use brute-force instead, while everything else uses the irradiance cache.

Settings

Mode/Filename

When "Mode" is set to "Rebuild (don't save)", Redshift volition compute a new irradiance cache from scratch (for each frame) but will not relieve it to disk. The frame will be rendered to completion.

When "Mode" is gear up to "Rebuild (prepass merely)", Redshift will compute a new irradiance cache from scratch (for each frame) and volition save it to the user-specified file. The concluding rendering pass will exist skipped.

When "Mode" is gear up to "Rebuild", Redshift will compute a new irradiance cache from scratch (for each frame) and will save information technology to the user-specified file. The frame will be rendered to completion.

When "Mode" is set to "Load", the computation phase is skipped and the data is loaded from the user-specified file. The frame will be rendered to completion.

Flythrough Mode

Enabling "Flythrough mode" allows Redshift to compute the current frame's irradiance cache points using the concluding frame's points. This mode should only be used on flythrough animations, i.eastward. just when the camera is moving. If any objects or lights motion, this mode will produce visual artifacts. Since this mode helps with structure of irradiance cache points, it'south merely available on the 2 "Rebuild" modes and is grayed out for "Load".

Number of frames to blend

The "Number of frames to alloy" parameter is but enabled when the "Mode" is set to "Load". It allows averaging the results of multiple irradiance cache files (ane for each frame) together in lodge to ameliorate whatever flickering furnishings that might be present because of insufficient quality settings and/or hard lighting situations. Delight refer to this section below for more than information on how to utilise the "Rebuild (prepass)" and "Load" modes. Since this fashion has to practise with loading and blending multiple frames before rendering, it's only bachelor for the "Load" style and is grayed out for the "Rebuild" modes.

Irradiance Cache data is view-dependant which ways that information technology has to exist re-generated when either the camera or any objects move. Information technology besides has to be regenerated if lights change (position or intensity) and if materials are adapted. However, there are a few settings that do not impact the irradiance cache:

All antialiasing settings
Whatsoever parameter that has to do with "number of samples". For instance "number of glossy rays", "number of expanse light samples", "depth of field num samples"

If you are making whatsoever terminal-minute adjustments to your frame and tweaking these kinds of parameters you can save some fourth dimension by re-using the irradiance cache you computed last time using the "Load" mode.

Testify Calculation

This option will bear witness a very rough estimate of the irradiance cache points as they are computed. It volition nearly certainly comprise racket and some visual glitches – don't worry, though, these are to exist expected!

Apply Separate Points For Secondary Rays

By default, points generated by primary (camera) rays are stored together with points generated by secondary rays such as reflection and refraction. While this is typically ok, sometimes there can be flickering artifacts acquired past this because the point densities tin can vary wildly. If you lot're getting flickering artifacts on scenes using reflections/refractions, this option volition care for the points separately and try to avoid such bug. Treating the points separately incurs a (typically) pocket-sized performance and storage price, so enabling this selection is advisable only if such flickering issues occur.

If you're getting irradiance cache flickering bug, we recommended rendering a few frames with and without reflections/refractions. Yous tin can globally enable/disable reflections/refractions in the Redshift Globals tab. Please ensure that y'all enable the "employ divide points for secondary rays" choice only if y'all are see flickering with reflections/refractions enabled and no flickering with reflection/refraction disabled!

Visualize Points

Enabling this will render the irradiance cache points equally small discs. We also add together a bit of color to each point to make sure that even near-black ones can be seen.

This way is useful in finding out if some settings are besides ambitious. For instance if you see a mostly flat part of the paradigm containing too many points this might (possibly) mean that "Color Threshold" is besides ambitious.

Using this mode tin also help users better understand the outcome that thresholds can have on the indicate densities.

Min-Max Rate

When the renderer computes the Irradiance Cache Points, it does that in multiple "resolution passes". It starts with a low-resolution pass and and then progressively renders at higher and college resolutions. The lower resolution passes take intendance of apartment surfaces or depression-contrast lighting and the higher resolution passes insert points around areas of more detail and/or contrast. In some ways, this is similar to how adaptive antialiasing works.

The Min-Max rates control the lowest and highest resolutions that the irradiance caching will utilize to insert points. Here's what the numbers mean:

-5 means "carve up resolution by 32"
-iv means "carve up resolution by 16"
-3 means "divide resolution by 8"
-2 means "split up resolution past 4"
-1 means "divide resolution past 2"
0 means "use final resolution"
ane means "utilise iv samples per terminal resolution pixel"

Example:

For a 1920x1080 frame a setting of (-3, 0) will render in 4 passes:

240x135
480x270
960x540
1920x1080

Most scenes will render fine with the default (-3, 0) setting. If your scene requires very high-resolution (like 4K, for instance) you might want to lower the min rate to something like -4 or -5, especially if it doesn't incorporate as well much detail.

If your scene contains sub-pixel detail, you might run into artifacts effectually that particular if you use a max charge per unit setting of 0. In these cases, it's appropriate that yous raise the max charge per unit to 1. Mostly speaking, if the max rate is non high plenty, small details will be missed and the final render might have GI artifacts appearing as also bright or dark pixels, splotches and light 'leaking'.

While working on your scene (and doing draft renders), these artifacts might non be as of import as rendering speed. For these cases, a max rate of -1 might provide reasonable results. For final renders, though, (and especially if you are rendering animations) information technology is advisable to employ a max rate of 0 or i.

Color/Distance/Normal Thresholds

As mentioned above, Irradiance Caching places fewer points on flat or low-contrast surfaces. Redshift provides three threshold parameters to allow the user to define what is considered "flat" or "low contrast". Later down in this certificate there are some visual examples showing how these parameters affect the final epitome quality.

The "Color Threshold" parameter detects dissimilarity in the irradiance enshroud points and inserts more of them around areas of high contrast. The lower you make this number, the sharper your GI shadows will be but also more points will have to be computed, which means longer rendering times. The values for this parameter should typically range betwixt 0.01 and 0.001. For draft renders you can set this to ii.0 which volition introduce the least amount of points and render the fastest but volition brand the GI shadows blurry and might too innovate flickering during animations. One thing that is important to remember is that you have to apply enough rays (described beneath) to get a reasonable corporeality of lighting smoothness on your irradiance cache points before lowing the color threshold parameter. Non doing and then will make the algorithm incorrectly remember that there is GI dissimilarity detail and volition introduce even more points.

The "Altitude Threshold" parameter controls the number of points near corners and creases. Corners and creases oft make GI alter rapidly so several irradiance enshroud points will be needed around them in club to take hold of these rapid lighting changes. At that place are "very low", "depression", "medium" and "high" quality settings. The higher the quality, the more points will be inserted. The default "medium" setting should piece of work fine for most cases. If you are doing draft renders you can use the "low" or "very depression" settings – this volition introduce the to the lowest degree amount of points around corners/creases and renderer the fastest just will brand corner GI lighting blurry (and mayhap splotchy) and might likewise introduce flickering during animations.
The "Normal Threshold" parameter controls how the curvature of objects affects the signal density. Just like corners and creases, curved surfaces too can translate into rapid changes of lighting. At that place are "low", "medium" and "loftier" quality settings for this parameter. A lower quality setting will insert fewer points on curved surfaces and vice-versa. The default "medium" setting should work fine for about cases. If lighting appears to be too soft or you're getting some flickering (during animations) on curved surfaces, you can endeavor using the "loftier" setting. During draft rendering you lot can employ the "low" setting which will innovate the least amount of points but will make GI lighting too soft on sharp curvatures and might also introduce flickering during animations.

Min Particular

The thresholds mentioned higher up might introduce a very loftier number of points which can utilize lots of retention and make rendering slower. The "Min Detail" parameter allows you lot to control the screen-infinite density of points in a global manner. A value of 2.0 means "try to not insert points that are closer than 2 pixels autonomously". A value of iv.0 is for four pixels, etc.

For terminal renders you should prepare this value to 0.0. For draft renders you tin can try increasing it to something like 4.0 or 8.0. The higher the number, the fewer points will be created which volition make the rendering faster only besides blurrier and potentially with animation flickering.

Radius Cistron

During final rendering, the irradiance cache points are used to interpolate final GI lighting. The "Radius factor" parameter allows the user to command the 'area of influence' of the irradiance cache points. Using large numbers volition make the GI lighting a bit blurrier but besides with fewer splotches. For the majority of cases you should apply a setting of 2.0. During typhoon renders (and with low quality threshold settings) y'all can endeavour a setting of 4.0.

Using values larger than two.0 might have some impact on memory and also terminal rendering performance.

Num Rays / Adaptive Amount / Adaptive Threshold

The "Num Rays" parameter controls the quality of each irradiance cache point. The lighting at each point is computed in a way similar to animal-force GI, i.due east. several rays are shot out of information technology. Using likewise few rays will introduce a "splotchy" upshot that is very distracting. Scenes that contain several lights (or fewer big lights) tin typically use fewer rays (betwixt 500 and 1000). If the scene contains very few vivid lights or not enough lighting is coming through pocket-size openings (windows) the number of rays might have to be increased a lot to get make clean results. We have seen architectural interior scenes that require numbers such as 2000 – 4000 for a perfectly clean outcome.

Not all irradiance cache points need the same number of rays. For case, some points might be in 'exposed' areas and can be seen by several lights – these points but need a few rays to get a clean result. Other points, on the other hand, might be hidden behind objects and might have a hard time finding low-cal – these points need more rays. Redshift takes care of this situation using adaptive sampling, i.e. it automatically adjusts the number of rays for each irradiance cache point. The user, though, has to specify a couple of parameters to help Redshift make the necessary choices during adaptive sampling,

The "Adaptive Amount" parameter controls the percentage of rays that should be shot initially. For instance, if "Num Rays" is m and "Adaptive Amount" is at 0.viii, this ways that 80% of the rays will exist adjusted (i.east. 800 rays) and the initial 20% of the rays volition be shot (i.e. 200 rays). If the value was at 0.3, this means that xxx% of the rays will exist adapted (300 rays) and 70% of the rays will exist shot (700 rays in this instance). So, the lower you make this number, the less adaptive the algorithm is. Setting this parameter to 0 means that Redshift will shoot all one thousand rays for each indicate. Scenes of reasonable contrast volition work fine with the default 0.85 value. If you even work with a scene that has extreme contrast (i.e. very potent indirect illumination coming from a modest light source, or a far abroad light source), information technology might be necessary to reduce this number to something similar 0.5 in guild to avoid 'early on termination' artifacts. Early termination is when the algorithm thinks that there no more lighting to be gathered and stops abruptly – even though there might exist more lighting that could have been gathered with more rays. Another way of fixing this issue is leaving the "Adaptive Amount" every bit-is but actually raising the "Num Samples". This ways that the algorithm will shoot more initial rays and will have a much amend take a chance of finding any 'difficult' light sources.

The "Adaptive Mistake Threshold" controls how many of the remaining rays volition exist used. Similar mentioned above, the algorithm always shoots a percentage of the rays initially. These initial rays are used to compute a contrast value which is compared against "Adaptive Error Threshold". The comparison defines how many more rays volition exist needed for that irradiance enshroud indicate. The lower this parameter, the more 'sensitive' the algorithm becomes - which ways that more rays will be shot. If your renders exhibit persistent 'splotches' (meaning: you increased the "Num Rays" just the results are notwithstanding not make clean) the reason might be "Adaptive Error Threshold": you could try reducing it to values similar 0.005 or even 0.001.

Num Smoothing Passes

Commonly, in order to remove splotchy artifacts one has to increment "Num Samples". A faster culling is to simply blur the irradiance cache points together. This is what "Num Smoothing Passes" does. Setting this parameter to zero volition practise no smoothing. The more smoothing passes y'all do, the smoother the final event.

Smoothing the results will crusade some loss of GI particular (shadows) and might introduce a bit of flickering in animations - but both of these issues might be acceptable during draft rendering. Commonly a value of 1 is an acceptable compromise: information technology rarely causes issues during animations, it only causes a bit of loss of sharpness and the final results do await smoother.

How To Use The Settings To Get A Clean Event

Here nosotros evidence some common issues you might encounter and how to suit your settings in order to solve these issues.

Example ane : Thin details accept splotches around them and/or are flickering during animation

Solution Step A: Ensure "Min Radius" is ready to zippo

Solution Pace B: Increment "Max rate"

Below we prove a uncomplicated scene that contains some sparse item on the wall. If the max rate is not high plenty you might meet the kind of artifact shown below. In these cases, increasing the max rate will assist reduce or eliminate the outcome.
Please note that the scenes beneath use strong antialiasing settings. We did this intentionally to prove that the problems are not related to antialiasing – which is a common misconception amongst users when they see this upshot.


Scene uses a "Min Charge per unit" of -three and a "Max Rate" of -1. The max rate being -ane is the reason why there are lighting artifacts effectually the sparse geometry	Increasing the max charge per unit to 0 solves these issues. Similarly, if you get artifacts with a "Max Charge per unit" of 0, you could increase it to 1.

Example two : The GI solution contains splotches in specific areas. At that place is 'crawling' around these areas in animations.

Solution Stride A: Increase "Num Rays" if information technology's relatively small (less than 1000 rays)

Solution Stride B: If "Num Rays" is already a large number (2000-3000 rays or more) decrease "Adaptive Fault Threshold"

Solution Footstep C: If "Num Rays" is already big and "Adaptive Mistake Threshold" is already pocket-sized, decrease "Adaptive Amount"

Even though Redshift uses an adaptive sampling scheme, information technology has to operate within certain user-defined parameters: "Num Rays", "Adaptive Mistake Threshold" and "Adaptive Corporeality". When these parameters are likewise constrained (for example: too few rays) rendering might be faster just it also introduces artifacts. Hither we show how to adjust these parameters to avoid visual artifacts.

Below is a scene that is using a small number of rays (100) and is showing visible splotches in corners. Adaptive Amount is 0.85 and Error Threshold is 0.01. Adjusting these 2 parameters would have no effect on the splotches considering the number of rays is too small. And then, in this case, the first thing nosotros should exercise is increase "Num Rays".


Using merely 100 rays. Splotches visible on wall corners and between the wall blades. Irradiance cache computation time: i.5 seconds.	Using 2000 rays. Splotches are improved a lot but the still some faint artifacts on the walls. Irradiance enshroud computation time: ii.4 seconds.

The second paradigm looks much ameliorate, merely still has a very faint issue on the wall/ceiling corner. Most of the fourth dimension this is not an outcome in still images but it might show up as a slight 'ripple' in animations.

The problem hither is that the default adaptive threshold of 0.01 is preventing the system from using enough rays. Halving it to 0.005 uses more rays but helps produce a clean result. This is shown below.

For a near-perfect frame nosotros decrease "Adaptive error threshold" to 0.005. Irradiance cache computation time: 3.8 seconds.

And so how exactly should someone adjust the "Adaptive Amount" and "Adaptive Error Threshold" parameters?
There are two principal problems that can come with improperly adjusted adaptive sampling parameters:

The adaptive mistake threshold is also high which means that not plenty rays will be used. This can cause splotchy results.
The adaptive amount is as well high which makes the algorithm terminate also early and miss lighting. Again, the consequence is splotchy GI.

Redshift's default "Adaptive Error Threshold" is 0.01. While this works ok for near scenes, equally information technology was shown to a higher place, it is appropriate that final renders employ a lower number such as 0.005 (i.e. half the default) or lower (e.g. 0.001). Generally speaking, afterward the user increases "Num Rays", "Adaptive Error Threshold" should exist the next thing to be adjusted.

What about the second outcome (terminating as well early on)? Adaptive sampling works by shooting an initial number of rays, computing a contrast and so, if the contrast is too high, shooting some more than rays to clean up the result. If "Adaptive Amount" is too high, and so besides few initial rays will be shot – and these might completely miss of import lighting. The algorithm then is fooled into thinking that there is no more than work to be done which stops the sampling. Stopping the sampling is called "early termination". Except, in this instance, the termination is too early on! The result is, you lot guessed it, splotches!

Most of the times, but increasing "Num Rays" will take care of this event and so you might never see this issue. This is considering a larger "Num Rays" ways a larger number of initial rays which means a smaller chance of missing important lighting. But, sometimes, lighting tin extremely hard to find. In these cases, you might have to decrease "Adaptive Amount".

The example beneath shows a thin translucent box that contains a very vivid point lite. It was rendered with a very loftier number of rays (8000) and a very low adaptive error threshold (0.001). Nevertheless, using the default 0.85 adaptive amount, it still exhibits serious artifacts most the bottom of the epitome. This is because these pixels are fairly far away from the light source and the initial rays fail to detect any lighting – so the algorithm creates irradiance cache points that are black. Lowering the adaptive amount to 0.5 improves the result.


"Adaptive Corporeality" set to the default 0.85. Visible artifacts tin can be seen on the lesser half of the prototype	"Adaptive Amount" set to 0.5. Although there are still some faint problems, this is a big improvement over the 0.85 example. This comes at the price of more than initial rays, though.

Case three : Irradiance cache results look as well blurry compared to creature-force

Solution Step A: Disable smoothing passes (if enabled)

Solution Step B: Reduce "Radius Cistron" (if more than than ii.0)

Solution Step C: Subtract "Colour Threshold", if lack of particular means blurry shadows

Solution Pace D: Use college quality settings for "Normal Threshold", if lack of detail ways besides blurry lighting on curved surfaces

Because irradiance caching doesn't compute GI on a per-pixel basis, it cannot provide quite the same corporeality of sharpness as the brute-force technique. Even so, by adjusting a few settings, you can often go fairly close to brute-force particular while still enjoying faster rendering times and grain-free results.

Let's look at a simple instance: a translucent box containing a point light casting some shadows. We will use a animate being-force rendering every bit reference.



Brute-force rendering. Notice the well-defined shadows.	Irradiance caching using default values. The shadows are blurred to the signal of being completely invisible.	Irradiance caching with blurring passes disabled, radius factor was left at ii.0, color threshold was reduced to 0.001. The shadows are at present more than visible.

While reducing the color threshold reclaimed some of the detail, nosotros propose doing so just if admittedly necessary. The reason is that reducing information technology will force many irradiance cache points to be computed. This volition increment rendering times and memory requirements. If this kind of fidelity is necessary, information technology's advisable that you use beast-forcefulness instead.

Please read "example 4" below for notes regarding reducing the color threshold.

So what about "Altitude Threshold" and "Normal Threshold"?

"Distance Threshold" should be typically left at "medium". While using the "high" setting will capture a chip more definition virtually corners and creases, "Color Threshold" volition oft catch those details too – and will do and so only when there is actual contrast. The couple of images below testify how lowering the distance threshold makes the shadow definition a fleck sharper most the pillars.


Default Values with Distance Threshold set to "Medium" (which is also the default)	Default Values With Distance Threshold prepare to "High". In that location is only a slight improvement near the base of the pillars.

Similarly, for "Normal Threshold", we propose using the default "Medium" setting. If you are rendering animations and your geometry is low-poly, using the "High" setting can assistance improve any flickering artifacts you lot might feel.

Case 4 : Lowering the "Colour Threshold" parameter is making my render take a lot longer and is more than splotchy!

Solution: Make sure that the GI solution is every bit make clean as possible earlier lowering "Color Threshold". Follow the steps outlined in "Case 2"

Similar mentioned earlier, the "Colour Threshold" parameter is useful when you want more definition around GI shadows. It works by comparing neighboring irradiance cache points and, if it detects discontinuities in the lighting, information technology inserts more irradiance cache points in guild to catch the extra item.

The problem is that discontinuities might be not because of an actual shadow only because of low irradiance cache settings! For example, setting "Num Rays" to a low number makes each irradiance cache point very noisy and different to its neighbors. When this happens, the algorithm backside "Color Threshold" might be fooled into thinking that there is actual particular there and volition continue adding more points. That tin make the frame take a lot longer to return and information technology will about certainly not improve the concluding result. In fact, in some cases, it can even make it worse!

So it'southward strongly advisable that, before you lower "Color Threshold", you lot adjust your "Num Rays" and "Adaptive Threshold" to get a smooth result – as described in "Example 2" in a higher place. Using the signal visualization characteristic can also aid detect when this upshot happens.

How to apply "Rebuild (prepass)" and "Load" modes to better/eliminate flickering artifacts

The performance benefits of the irradiance cache lie on the fact that expensive GI computations are interpolate and are not executed on each and every pixel. However, this interpolation can sometimes miss important lighting information and can cause flickering artifacts on animations. This typically happens if:

The settings are not sufficiently loftier (eastward.g. num rays)
The geometry has certain irregularities or very small detail
The lighting conditions are 'difficult', i.east. but pocket-size parts of the scene are lit by direct lighting

If y'all encounter any such artifacts, yous tin try the following procedure:

Commencement, select "Rebuild (prepass)" and select an appropriate filename – or use the default filename.
If you are using the irradiance point cloud for secondary GI bounces, set its mode to "Rebuild". If you don't want the irradiance cache files to be saved, clear its "Filename" box.
Render your animation. During rendering, one irradiance cache file for each frame volition be generated just the final rendering pass volition be skipped.
Then, select the "Load" mode and arrange the "number of frames to blend" parameter. Render your animation. For each frame, Redshift volition now load a number of 'neighboring frame' irradiance enshroud files, alloy them together and use the composite result to return the final frame. Considering of this inter-frame blending, any temporal artifacts (flickering) will be reduced or even eliminated.

The "number of frames to blend" parameter controls how many 'neighboring' irradiance cache files volition exist loaded and blended together. For example, a setting of 2 ways "load the previous ii and next ii frames". So, for this example, the algorithm will blend four neighboring frames plus the current frame, i.east. 5 frames together. A setting of i means "load the previous and adjacent frames", and so 3 frames will be blended together.

Larger numbers of blended frames means less flickering. However, blending too many frames together can create a light 'ghosting' or 'lagging' effect in scenes with fast moving objects or lights. If your irradiance cache settings are properly adjusted, a setting between 2 and 4 should exist sufficient to improve artifacts to the signal of either beingness completely eliminated or barely visible.

Irradiance enshroud files can be large so be sure to select a folder/drive that has enough free infinite.

Memory Considerations

If yous are rendering very loftier-resolution images or moderate resolutions only the scene contains a lot of detail, you might become an error regarding the points non fitting in the allotted GPU retention infinite. The message will read similar this:

Irradiance enshroud points don't fit in VRAM. Frame aborted. Please either reduce Irradiance Cache quality settings or increase the  irradiance enshroud memory budget in the retention options

If your settings are just right and don't desire to change them, the easiest affair to practise is simply increase the memory budget. By default, Redshift reserves 64MB for the irradiance cache. You can endeavor raising this number to fourscore, 100 or larger. To edit the Irradiance Cache memory upkeep, become to Redshift options, Memory Tab and modify the parameter called "Irradiance cache working tree reserved retentiveness". The parameter units are in megabytes.

Alternatively, you might desire to modify Irradiance Caching parameters that touch on the number of generated points:

Increase "Min Detail". This is a global parameter that used to preclude besides many Irradiance Cache points from being generated. For high-resolution frames you tin can effort increasing that to values like 2 or four.
Lower "Max Rate". If it's set to 1, yous might want to attempt 0. If the frame is very high-resolution (for example, 4K) you might even desire to try -1
Increment "Color Threshold". Getting really good GI shadow definition can take a lot of points. If your frame already contains interesting shadows from direct lights, the sharpness of the extra GI shadows might not be as important. This is specially true if you are using techniques such as "Portal Lights".
Lower "Normal Threshold". If this is set to 8 or college, this might exist overkill. Attempt a value like 4, instead.